Email sent to an account on the same server causes smtp service to hang

Maintenance
1

Hi,

I’ve recently added other account to my miab instance (some of the same domain and some from other domains). I’ve noticed that emails going in and out to email addresses not managed on my miab instance work just fine (gmail), but if an email is sent to an account that is managed by my instance, it causes my server to hang.

Once the server is rebooted the email appears in the other account’s inbox, but if I don’t reboot the server remains unresponsive.

I recorded the following from the nginx error logs:
2018/12/07 23:56:06 [error] 1407#0: *952 upstream timed out (110: Connection timed out) while reading response header from upstream, client: 127.0.0.1, server: my.server.domain, request: "OPTIONS /caldav/calendars/user@account.email/ HTTP/1.1", upstream: "https://127.0.0.1:443/cloud/remote.php/caldav/calendars/user@account.email/", host: "127.0.0.1"

This error repeats itself for all the accounts on the server.

I get the following from the access log:
<server ip> - user@account.email [08/Dec/2018:00:02:08 -0500] "POST /Microsoft-Server-ActiveSync?jBAJBBBOaW5lfy78dvzg4MkIwNTc0BAgb0iAHQW5kcm9pZAcBAA== HTTP/1.1" 401 5 "-" "Nine-Onyx_00WW/PPR1.180610.011"

This appears for each account on the server. “Nine-Onyx” is the Android client I use to send/receive my emails.

Any ideas what could cause the server to hang like this?

2

Extra info:

The email service appeared to be unresponsive again, but this time without having sent an email internally. This is the error message that appears in the nginx error log:

2018/12/08 09:18:49 [error] 1496#0: *351 upstream timed out (110: Connection timed out) while reading response header from upstream, client: <ip address>, server: my.mail.server, request: "POST /Microsoft-Server-ActiveSync?jBIJBBBOaW5lQkRGMzg4MkIwNTc0BAB9jRgHQW5H38kpZAcBAA== HTTP/1.1", upstream: "fastcgi://unix:/var/run/php/php7.0-fpm.sock", host: "my.mail.server"

This error is repeated for each account on the server.

3

Sorry, it is hard for me to follow what exactly your configuration is for MIAB. Did you edit configuration files, or did you use MIAB’s web interface to make the configuration?

I don’t really understand what you’ve done with your server. If you can blackout sensitive information, or if you don’t care about security, could you please post a screenshot of your configuration here?