Email are getting stuck in email queue

[NehaNagori]

Most of the mails from JIRA are getting stuck in email queue. They are going into the error queue. If I resend error queue and flush email queue. They are again going into the error queue. 

[NehaNagori]

I used to delete error queue daily. I didn't find any thing wrong in logs.

Also, one email, multiple queues are generating.

[Jobin Kuruvilla [Adaptavist]]

When a mail goes to the error queue, there should be something in the atlassian-jira.log file that indicates the reason. Did you check the log yet?

[AKSHAY THAKARE]

where is log present

[Santosh Maurya]

Hi Neha,

There could be some permanent issue with those emails, check if they have attachments more then 10MB or have problem with their recipents.. would suggest to delete the error queue..

[NehaNagori]

Hi Santosh,

Thanks for replying!

I used to delete error queue, But I am facing this problem after 2-3 days. 

The problem is even coming after assigning an issue to an assignee. Mail is not going to the assignee. and its a very basic requirement.