SMTP connect takes minutes with many IMAP accounts

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Posts: 1
Joined: November 8th, 2017, 3:16 am

Post Posted November 8th, 2017, 3:31 am

My TB manages 47 IMAP accounts being served on my own server.
The amount of accounts has grown over the last four months.
Since its been >30 IMAP accounts, TB takes very long to connect to my SMTP server when sending out a new email.

This is what happens:
1) I write a new email
2) I click on "Send"
3) The busy pointer spins
4) CPU time of process thunderbird reaches ~40%
5) Mail is sent after 4 minutes

When I write a second mail on the same IMAP account, it is send immediately.
I suggest that there is an internal limit of cached SMTP connections.
How to increase it?


Posts: 3
Joined: November 8th, 2017, 6:40 am

Post Posted November 8th, 2017, 6:41 am

Same here. What seems to work for now is cancelling Send, try again, sometimes a third time, and then it goes through. But it is annoying.


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Posts: 43356
Joined: July 30th, 2003, 5:06 pm

Post Posted November 8th, 2017, 9:26 pm

Try temporarily running in safe mode via help -> restart with add-ons disabled to rule out it being a side effect of an add-on that doesn't work well with the latest version of Thunderbird.

The problems with the SMTP server shouldn't depend upon whether or not you use a POP or IMAP account, unless its a delay caused by saving a copy of the sent message in a remote folder, or the same server is used for both IMAP and SMTP. See if temporarily using a sent folder in "local folders" makes a difference. Log into Cpanel or whatever you use to admin your server and see if you have any per node, per user or global connection limits that it might be running into.

See if you want to enable SMTP logging.

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