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With the API source, apps like JEMH can drive EMQ with a pre-rendered and pre-built email. In this scenario, the email will already be fully populated with a from: address. When Digest Delivery is being done, the sender address is not retained, only the body html/text is. Therefore digest delivery will continue to use the Queue specific sender address for mail that EMQ creates with the digested content within. The main issue here comes up with Immediate Delivery and is covered below.

Immediate Delivery

The unhappy path of a different mail from: address to the queue from: default

The problem that can come up is with Immediate Delivery is being done where EMQ will take the email supplied by the API source and use that verbatim, sending to the queue SMTP server for delivery. Whether the queue SMTP server allows the from: address to be what you have configured is mail-server dependant. Gmail for example will fallback to the ‘default’ mailbox sender address ‘and just work’, O365 will likely fail with:

Code Block
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MailException: com.sun.mail.smtp.SMTPSendFailedException: 554 5.2.0 STOREDRV.Submission.Exception:SendAsDeniedException.MapiExceptionSendAsDenied; Failed to process message due to a permanent exception with message Cannot submit message.

The important keyword is MapiExceptionSendAsDenied, which leads to:

To diagnose this kind of thing, you will need to look to the logs to resolve differences between the queue authentication / from: address, and what the mail from: address actually was. Simply, if your queue account is not able to send on behalf of the address you nominate, the mail will not send, and this will block the sending queue.

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JEMH Logging (success)

This is from the jemh.log showing that JEMH built the email and piped through to EMQ.

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2021-03-13 16:24:43,308 http-nio-8080-exec-16 DEBUG [jira.emh.service.DefaultJEMHMessageManager] digestNotification() TEST-5 for recipient: assignee@localhost
2021-03-13 16:24:43,308 http-nio-8080-exec-16 DEBUG [jira.emh.service.DefaultJEMHMessageManager] --- Digest starting
2021-03-13 16:24:43,308 http-nio-8080-exec-16 DEBUG [service.optional.emq.EmqAccessor] The EMQ Service Class IEMQOperationsManager is available, getting the ServiceFactory
2021-03-13 16:24:43,309 http-nio-8080-exec-16 DEBUG [emh.service.optional.OptionalService] tracked service: com.thepluginpeople.jira.emq.queue.EMQOperationsManagerImpl@3622f4bf
2021-03-13 16:24:43,309 http-nio-8080-exec-16 DEBUG [service.optional.emq.Emq] EMQ is available
2021-03-13 16:24:43,346 http-nio-8080-exec-16 DEBUG [jira.emh.service.DefaultJEMHMessageManager] --- Digest ended

JEMH Logging (failure)

This is also from the jemh.log, it shows the outcome when EMQ is not configured to listen to the API. JEMH will trigger a default delivery in this case using the standard Jira mail server. EMQ itself, listening to Jira events, will also get that event and queue a delivery.

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2021-03-13 16:18:06,889 http-nio-8080-exec-1 DEBUG [jira.emh.service.DefaultJEMHMessageManager] digestNotification() TEST-5 for recipient: reporter@localhost
2021-03-13 16:18:06,889 http-nio-8080-exec-1 DEBUG [jira.emh.service.DefaultJEMHMessageManager] --- Digest starting
2021-03-13 16:18:06,890 http-nio-8080-exec-1 DEBUG [service.optional.emq.EmqAccessor] The EMQ Service Class IEMQOperationsManager is available, getting the ServiceFactory
2021-03-13 16:18:06,890 http-nio-8080-exec-1 DEBUG [emh.service.optional.OptionalService] tracked service: com.thepluginpeople.jira.emq.queue.EMQOperationsManagerImpl@3622f4bf
2021-03-13 16:18:06,890 http-nio-8080-exec-1 DEBUG [service.optional.emq.Emq] EMQ is available
2021-03-13 16:18:06,890 http-nio-8080-exec-1 DEBUG [jira.emh.service.DefaultJEMHMessageManager] --- Digest ended
2021-03-13 16:18:06,890 http-nio-8080-exec-1 ERROR [jira.emh.service.DefaultJEMHMessageManager] Message was NOT digested for some reason, fallbacking back to standard delivery

Immediate Delivery

Queue Selection

When driven through the API, the calling app (typically JEMH) can also supply a numeric queueId that would be used to drive delivery. If no queueId is defined, and if no queue ‘matches’ the causal IssueEvent (typically by project) then default queue will be used. This lack of queue definition can lead to a mismatch between the built email’s from: address, and the sending account, covered next.

When the API delivered mail has a from: address different to the queue’s

The problem that can come up is with Immediate Delivery is being done where EMQ will take the email supplied by the API source and use that verbatim, sending to the queue SMTP server for delivery. Whether the queue SMTP server allows the from: address to be what you have configured is mail-server dependant. Gmail for example will fallback to the ‘default’ mailbox sender address ‘and just work’, O365 will likely fail with:

Code Block
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MailException: com.sun.mail.smtp.SMTPSendFailedException: 554 5.2.0 STOREDRV.Submission.Exception:SendAsDeniedException.MapiExceptionSendAsDenied; Failed to process message due to a permanent exception with message Cannot submit message.

The important keyword is MapiExceptionSendAsDenied, which leads to:

To diagnose this kind of thing, you will need to look to the logs to resolve differences between the queue authentication / from: address, and what the mail from: address actually was. Simply, if your queue account is not able to send on behalf of the address you nominate, the mail will not send, and this will block the sending queue.

Happy path logging from API

The mail is received, and queued for delivery

Code Block
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2021-03-13 16:42:30,652 http-nio-8080-exec-13 DEBUG [jira.emq.queue.EMQBootstrap] digestNotification() for usable event: TEST-5, subject: (TEST-5) This is a starting email template, update as required
2021-03-13 16:42:30,655 http-nio-8080-exec-13 DEBUG [jira.emq.queue.QueueManagerImpl] Matched DEFAULT queue [EMQ TEST project queue with "EMQ default" mailbox] for event 6 on TEST-5
2021-03-13 16:42:30,660 http-nio-8080-exec-13 DEBUG [jira.emq.queue.JiraServiceUtils] Email match [assignee@localhost] with [key=JIRAUSER10100,username=assignee, email=assignee@localhost]
2021-03-13 16:42:30,660 http-nio-8080-exec-13 DEBUG [jira.emq.queue.JiraServiceUtils] User assignee is active, getting directoryUser
2021-03-13 16:42:30,660 http-nio-8080-exec-13 DEBUG [jira.emq.queue.JiraServiceUtils] Got ACTIVE directory user: assignee, directoryId: 1
2021-03-13 16:42:30,669 http-nio-8080-exec-13 DEBUG [jira.emq.queue.ActionEvaluatorImpl] Action IMMEDIATE resolved for [username=assignee, email=assignee@localhost, userkey=JIRAUSER10100]
2021-03-13 16:42:30,690 http-nio-8080-exec-13 DEBUG [jira.emq.manager.MailEntityManagerImpl] Mail Entity 16 has been created.
2021-03-13 16:42:30,691 http-nio-8080-exec-13 DEBUG [jira.emq.queue.MailEntityProcessorImpl] 1 mail items to be sent soon using queue 1 EMQ TEST project queue with "EMQ default" mailbox
2021-03-13 16:42:30,691 pool-66-thread-1 DEBUG [jira.emq.queue.MailEntityProcessorImpl] Mail Entity Processor Task has been created
2021-03-13 16:42:30,691 pool-66-thread-1 DEBUG [jira.emq.queue.MailEntityProcessorImpl] Waiting 10000 ms before more mail is sent
2021-03-13 16:42:30,692 pool-66-thread-1 DEBUG [jira.emq.queue.MailEntityProcessorImpl] Collected Mail Entity [id=16, qId=1, qName=EMQ TEST project queue with "EMQ default" mailbox] for delivery [type=IMMEDIATE]
2021-03-13 16:42:30,692 pool-66-thread-1 DEBUG [jira.emq.queue.MailEntityProcessorImpl] Waiting 10000 ms before more mail is sent

The mail is then sent a little while after

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2021-03-13 16:42:40,692 pool-66-thread-1 DEBUG [jira.emq.queue.MailEntityProcessorImpl] No new Mail Entities found
2021-03-13 16:42:40,692 pool-66-thread-1 DEBUG [jira.emq.queue.MailEntityProcessorImpl] Sending 1 collected Mail Entities
2021-03-13 16:42:40,695 pool-66-thread-1 DEBUG [jira.emq.queue.MailSenderJiraSMTPImpl] Starting to open connection
2021-03-13 16:42:40,707 pool-66-thread-1 DEBUG [jira.emq.queue.MailSenderJiraSMTPImpl] Connection [host:smtp.mailtrap.io, from: emq-default@blah.com] opened
2021-03-13 16:42:40,712 pool-66-thread-1 DEBUG [jira.emq.queue.MailQueueSenderImpl] 1 mail items to be sent NOW using queue 1: EMQ TEST project queue with "EMQ default" mailbox
2021-03-13 16:42:40,764 pool-66-thread-1 DEBUG [jira.emq.queue.AttachmentDownloaderImpl] Trying to download image from 'http://localhost:8080/images/mail/atlassian-email-logo.png' for inlining 
2021-03-13 16:42:40,766 pool-66-thread-1 DEBUG [jira.emq.queue.MailQueueSenderImpl] Sleeping for 100 ms before sending a new email
2021-03-13 16:42:40,867 pool-66-thread-1 DEBUG [jira.emq.queue.MailQueueSenderImpl] Sending Mail Entity 16 using connection [qId=3, qName=EMQ default, qFrom=emq-default@blah.com] with actual msg from: jiradefault@blah.com
2021-03-13 16:42:42,276 pool-66-thread-1 DEBUG [jira.emq.queue.MailSenderJiraSMTPImpl] Message [from=jiradefault@blah.com, subject=(TEST-5) This is a starting email template, update as required] sent in 1408 ms
2021-03-13 16:42:42,283 pool-66-thread-1 DEBUG [jira.emq.queue.MailQueueSenderImpl] Sending Mail Entity 16 has been sent using connection [qId=3, qName=EMQ default, qFrom=emq-default@blah.com] with actual msg from: jiradefault@blah.com
2021-03-13 16:42:42,283 pool-66-thread-1 DEBUG [jira.emq.queue.MailSenderJiraSMTPImpl] Closing SMTP server session [id=null, host=smtp.mailtrap.io, user=edbb06bded0edb, defaultFrom=emq-default@blah.com]
2021-03-13 16:42:42,285 pool-66-thread-1 DEBUG [jira.emq.queue.MailEntityProcessorImpl] Waiting 10000 ms before more mail is sent
2021-03-13 16:42:52,285 pool-66-thread-1 DEBUG [jira.emq.queue.MailEntityProcessorImpl] No new Mail Entities found
2021-03-13 16:42:52,285 pool-66-thread-1 DEBUG [jira.emq.queue.MailEntityProcessorImpl] Mail Entity Processor Task has finished

Immediate Delivery Auditing

The EMQ > Auditing > Mail Items then shows the mail sent by immediate delivery.

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The drop-down, circled above, gives access details of the sent mail, it includes details of the queue, and the from: address that the message had.

In the report below, an empty “qFrom:” in the (info) section means that no additional email was defined on the queue, and the default set in the Mail Connection would be used.

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Received immediate delivery mail

We use mailtrap.io for lots of email testing, it allows a dead end SMTP mailbox to be delivered to (with any from/to detail) without actually delivering to real mailbox recipients, we can use it to verify delivery and details within the sent mails.

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Mail source, showing (1) from: set by the API client, in this case, we can show it’s from JEMH (2).

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Immediate Delivery with a nominated queueId

The ID of the EMQ Queue is not as visible as it could be, it can be found on the edit screen URL in the browser:

Code Block
http://localhost:8080/plugins/servlet/emq/general-configuration#/mailConfiguration/mailQueue/2

Here we show an issue with a custom field containing the same queueId (1) and the custom from address that JEMH would use (2):

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(info) catch-22, for immediate delivery, setting the ‘custom from address custom field’ is only possible during edit when EMQ is not enabled - we typically expected Digesting delivery, here the JEMH Notification config is shown during edit without EMQ enabled (just to set this):

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And in JEMH, that custom field selected in the JEMH Notification config (the name is shown during edit)

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Log output showing how queueId “2” is fed into EMQ.

Code Block
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2021-03-13 17:59:31,116 http-nio-8080-exec-15 DEBUG [jira.emq.queue.EMQBootstrap] digestNotification() has event: TEST-5, queueId=2, subject: (TEST-5) This is a starting email template, update as required
2021-03-13 17:59:31,121 http-nio-8080-exec-15 DEBUG [jira.emq.queue.JiraServiceUtils] Email match [assignee@localhost] with [key=JIRAUSER10100,username=assignee, email=assignee@localhost]
2021-03-13 17:59:31,121 http-nio-8080-exec-15 DEBUG [jira.emq.queue.JiraServiceUtils] User assignee is active, getting directoryUser
2021-03-13 17:59:31,121 http-nio-8080-exec-15 DEBUG [jira.emq.queue.JiraServiceUtils] Got ACTIVE directory user: assignee, directoryId: 1
2021-03-13 17:59:31,130 http-nio-8080-exec-15 DEBUG [jira.emq.queue.ActionEvaluatorImpl] Action IMMEDIATE resolved for [username=assignee, email=assignee@localhost, userkey=JIRAUSER10100]
2021-03-13 17:59:31,142 http-nio-8080-exec-15 DEBUG [jira.emq.manager.MailEntityManagerImpl] Mail Entity 20 has been created.
2021-03-13 17:59:31,143 http-nio-8080-exec-15 DEBUG [jira.emq.queue.MailEntityProcessorImpl] 1 mail items to be sent soon using queue 2 Queue for TEST Project
2021-03-13 17:59:31,144 pool-84-thread-1 DEBUG [jira.emq.queue.MailEntityProcessorImpl] Mail Entity Processor Task has been created
2021-03-13 17:59:31,144 pool-84-thread-1 DEBUG [jira.emq.queue.MailEntityProcessorImpl] Waiting 10000 ms before more mail is sent
2021-03-13 17:59:31,144 pool-84-thread-1 DEBUG [jira.emq.queue.MailEntityProcessorImpl] Collected Mail Entity [id=20, qId=2, qName=Queue for TEST Project] for delivery [type=IMMEDIATE]
2021-03-13 17:59:31,145 pool-84-thread-1 DEBUG [jira.emq.queue.MailEntityProcessorImpl] Waiting 10000 ms before more mail is sent
2021-03-13 17:59:41,145 pool-84-thread-1 DEBUG [jira.emq.queue.MailEntityProcessorImpl] No new Mail Entities found
2021-03-13 17:59:41,145 pool-84-thread-1 DEBUG [jira.emq.queue.MailEntityProcessorImpl] Sending 1 collected Mail Entities
2021-03-13 17:59:41,145 pool-84-thread-1 DEBUG [jira.emq.queue.MailSenderJiraSMTPImpl] Starting to open connection
2021-03-13 17:59:41,147 pool-84-thread-1 DEBUG [jira.emq.queue.MailSenderJiraSMTPImpl] Connection [host:smtp.mailtrap.io, from: emq2@blah.com] opened
2021-03-13 17:59:41,148 pool-84-thread-1 DEBUG [jira.emq.queue.MailQueueSenderImpl] 1 mail items to be sent NOW using queue 2: Queue for TEST Project
2021-03-13 17:59:41,166 pool-84-thread-1 DEBUG [jira.emq.queue.AttachmentDownloaderImpl] Trying to download image from 'http://localhost:8080/images/mail/atlassian-email-logo.png' for inlining 
2021-03-13 17:59:41,168 pool-84-thread-1 DEBUG [jira.emq.queue.MailQueueSenderImpl] Sleeping for 100 ms before sending a new email
2021-03-13 17:59:41,268 pool-84-thread-1 DEBUG [jira.emq.queue.MailQueueSenderImpl] Sending Mail Entity 20 using connection [qId=2, qName=EMQ mailbox 2, qFrom=emq2@blah.com] with actual msg from: emq2@blah.com
2021-03-13 17:59:42,664 pool-84-thread-1 DEBUG [jira.emq.queue.MailSenderJiraSMTPImpl] Message [from=emq2@blah.com, subject=(TEST-5) This is a starting email template, update as required] sent in 1396 ms
2021-03-13 17:59:42,674 pool-84-thread-1 DEBUG [jira.emq.queue.MailQueueSenderImpl] Sending Mail Entity 20 has been sent using connection [qId=2, qName=EMQ mailbox 2, qFrom=emq2@blah.com] with actual msg from: emq2@blah.com
2021-03-13 17:59:42,674 pool-84-thread-1 DEBUG [jira.emq.queue.MailSenderJiraSMTPImpl] Closing SMTP server session [id=null, host=smtp.mailtrap.io, user=bc8b5b4f805e1c, defaultFrom=emq2@blah.com]
2021-03-13 17:59:42,677 pool-84-thread-1 DEBUG [jira.emq.queue.MailEntityProcessorImpl] Waiting 10000 ms before more mail is sent

The mail received:

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The headers show that the from: address is the expected emq2@blah.com, defined in the issue custom field, so if the smtp account used considers this valid, it will be delivered!

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Digested Delivery

The API digest path is similar to the Jira event path, we get an email, that's already rendered, so we pull the text/html content from the mail if its there, text/plain if not, and digest that.

The content is consumed:

Code Block
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2021-03-13 17:19:39,185 http-nio-8080-exec-22 DEBUG [jira.emq.queue.EMQBootstrap] digestNotification() for usable event: TEST-5, subject: (TEST-5) This is a starting email template, update as required
2021-03-13 17:19:39,187 http-nio-8080-exec-22 DEBUG [jira.emq.queue.QueueManagerImpl] Matched DEFAULT queue [EMQ TEST project queue with "EMQ default" mailbox] for event 6 on TEST-5
2021-03-13 17:19:39,193 http-nio-8080-exec-22 DEBUG [jira.emq.queue.JiraServiceUtils] Email match [assignee@localhost] with [key=JIRAUSER10100,username=assignee, email=assignee@localhost]
2021-03-13 17:19:39,193 http-nio-8080-exec-22 DEBUG [jira.emq.queue.JiraServiceUtils] User assignee is active, getting directoryUser
2021-03-13 17:19:39,193 http-nio-8080-exec-22 DEBUG [jira.emq.queue.JiraServiceUtils] Got ACTIVE directory user: assignee, directoryId: 1
2021-03-13 17:19:39,202 http-nio-8080-exec-22 DEBUG [jira.emq.queue.ActionEvaluatorImpl] Action DIGEST resolved for [username=assignee, email=assignee@localhost, userkey=JIRAUSER10100]
2021-03-13 17:19:39,215 http-nio-8080-exec-22 DEBUG [jira.emq.manager.DigestEntityManagerImpl] Digest Entity 20 has been created.

We can also see the API delivered content in EMQ > Auditing > Digest Items:

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The EMQScheduledFlushJob kicks in to process digest entries:

Code Block
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2021-03-13 17:20:07,515 Caesium-1-2 DEBUG [service.scheduler.impl.PluginJobRunnerImpl] Running job type: EMQScheduledFlushJob
2021-03-13 17:20:07,515 Caesium-1-2 DEBUG [service.scheduler.jobs.EMQScheduledFlushJob] Flushing queues
2021-03-13 17:20:07,534 Caesium-1-2 DEBUG [jira.emq.queue.DigestEntityProcessorImpl] 1 Digest Entities will be processed now.
2021-03-13 17:20:07,544 Caesium-1-2 DEBUG [service.scheduler.jobs.EMQScheduledFlushJob] Next job scheduled for : Sat Mar 13 17:25:07 GMT 2021
2021-03-13 17:20:07,600 pool-73-thread-1 DEBUG [jira.emq.manager.MailEntityManagerImpl] Mail Entity 17 has been created.

Mail Items are generated by the job for delivery,

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Again, the Report is accessed by the drop-down, circled above:

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The EMQScheduledFlushJob kicks in to flush mail that has been queued:

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2021-03-13 17:22:07,517 Caesium-1-2 DEBUG [service.scheduler.impl.PluginJobRunnerImpl] Running job type: EMQScheduledFlushJob
2021-03-13 17:22:07,523 Caesium-1-2 DEBUG [jira.emq.queue.MailEntityProcessorImpl] 1 mail items to be sent soon using queue 1 EMQ TEST project queue with "EMQ default" mailbox
2021-03-13 17:22:07,526 pool-75-thread-1 DEBUG [jira.emq.queue.MailEntityProcessorImpl] Mail Entity Processor Task has been created
2021-03-13 17:22:07,526 pool-75-thread-1 DEBUG [jira.emq.queue.MailEntityProcessorImpl] Polling for a new item without waiting.
2021-03-13 17:22:07,526 pool-75-thread-1 DEBUG [jira.emq.queue.MailEntityProcessorImpl] Collected Mail Entity [id=17, qId=1, qName=EMQ TEST project queue with "EMQ default" mailbox] for delivery [type=DIGESTED]
2021-03-13 17:22:07,526 pool-75-thread-1 DEBUG [jira.emq.queue.MailEntityProcessorImpl] Polling for a new item without waiting.
2021-03-13 17:22:07,526 pool-75-thread-1 DEBUG [jira.emq.queue.MailEntityProcessorImpl] No new Mail Entities found
2021-03-13 17:22:07,526 pool-75-thread-1 DEBUG [jira.emq.queue.MailEntityProcessorImpl] Sending 1 collected Mail Entities
2021-03-13 17:22:07,528 pool-75-thread-1 DEBUG [jira.emq.queue.MailSenderJiraSMTPImpl] Starting to open connection
2021-03-13 17:22:07,540 pool-75-thread-1 DEBUG [jira.emq.queue.MailSenderJiraSMTPImpl] Connection [host:smtp.mailtrap.io, from: emq-default@blah.com] opened
2021-03-13 17:22:07,544 pool-75-thread-1 DEBUG [jira.emq.queue.MailQueueSenderImpl] 1 mail items to be sent NOW using queue 1: EMQ TEST project queue with "EMQ default" mailbox
2021-03-13 17:22:07,581 pool-75-thread-1 DEBUG [jira.emq.queue.AttachmentDownloaderImpl] Trying to download image from 'http://localhost:8080/secure/viewavatar?size=xsmall&avatarId=10318&avatarType=issuetype' for inlining 
2021-03-13 17:22:07,587 pool-75-thread-1 DEBUG [jira.emq.queue.AttachmentDownloaderImpl] Trying to download image from 'http://localhost:8080/images/icons/priorities/medium.svg' for inlining 
2021-03-13 17:22:07,608 pool-75-thread-1 DEBUG [jira.emq.queue.MailQueueSenderImpl] Sleeping for 100 ms before sending a new email
2021-03-13 17:22:07,708 pool-75-thread-1 DEBUG [jira.emq.queue.MailQueueSenderImpl] Sending Mail Entity 17 using connection [qId=3, qName=EMQ default, qFrom=emq-default@blah.com] with actual msg from: emq-default@blah.com
2021-03-13 17:22:09,106 pool-75-thread-1 DEBUG [jira.emq.queue.MailSenderJiraSMTPImpl] Message [from=emq-default@blah.com, subject=EMQ Issue Digest: EMQ TEST project queue with "EMQ default" mailbox - #1 - 13 Mar] sent in 1398 ms
2021-03-13 17:22:09,108 pool-75-thread-1 DEBUG [jira.emq.queue.MailQueueSenderImpl] Sending Mail Entity 17 has been sent using connection [qId=3, qName=EMQ default, qFrom=emq-default@blah.com] with actual msg from: emq-default@blah.com
2021-03-13 17:22:09,108 pool-75-thread-1 DEBUG [jira.emq.queue.MailSenderJiraSMTPImpl] Closing SMTP server session [id=null, host=smtp.mailtrap.io, user=edbb06bded0edb, defaultFrom=emq-default@blah.com]
2021-03-13 17:22:09,109 pool-75-thread-1 DEBUG [jira.emq.queue.MailEntityProcessorImpl] Polling for a new item without waiting.
2021-03-13 17:22:09,109 pool-75-thread-1 DEBUG [jira.emq.queue.MailEntityProcessorImpl] No new Mail Entities found
2021-03-13 17:22:09,109 pool-75-thread-1 DEBUG [jira.emq.queue.MailEntityProcessorImpl] Mail Entity Processor Task has finished
2021-03-13 17:22:13,940 Caesium-1-4 DEBUG [service.scheduler.impl.PluginJobRunnerImpl] Running job type: EMQFlushMonitorJob
2021-03-13 17:22:13,941 Caesium-1-4 DEBUG [service.scheduler.jobs.EMQFlushMonitorJob] Flush Monitor job running
2021-03-13 17:22:13,942 Caesium-1-4 DEBUG [service.scheduler.impl.PluginScheduleManagerImpl] Job[EMQScheduledFlushJob] is OK and has yet to run, next run: Sat Mar 13 17:24:07 GMT 2021
2021-03-13 17:22:13,942 Caesium-1-4 INFO [service.scheduler.jobs.EMQFlushMonitorJob] [Jira Server] will test for IMMEDS
2021-03-13 17:22:13,944 Caesium-1-4 DEBUG [service.scheduler.jobs.EMQFlushMonitorJob] [Jira SERVER] No unsent IMMEDIATE delivery messages found

The EMQ > Auditing > Digest History shows the 17:22 flush:

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