Zabbix email messageId header

[axehind]

Hi all,
We are running zabbix 5.0.
We have been noticing that emails from zabbix are getting rejected by gmail now. The mail log is showing this being the reason

2022-08-18T13:21:08+00:00 [email protected] postfix/smtp[15674]: D3CDB82ACA4: to=<[email protected]>, relay=ASPMX.L.GOOGLE.com[172.253.63.26]:25, delay=0.22, delays=0.05/0/0.06/0.11, dsn=5.7.1, status=bounced (host ASPMX.L.GOOGLE.com[172.253.63.26] said: 550-5.7.1 [74.xxx.xxx.xxx] Messages missing a valid messageId header are not 550 5.7.1 accepted. j13-20020ac8404d000000b003434c3bcadfsi653091qtl.146 - gsmtp (in reply to end of DATA command))

Has anyone else been having this issue and found a solution? From my research, the email header formatting is done in the zabbix server C code and would require a whole recompile of the code to be able to add the messageId header to it. Is there another solution?

[carl]

I came across your thread while looking into the problem non-with zabbix, but a long time zabbix user.

It seems Gmail has recently made a change, seeing lots of posts like this from within the last month: https://www.mail-archive.com/mailop@.../msg16468.html

I haven't seen zabbix failing myself though, I wonder if this is because we send via localhost/postfix/sendmail/smarthost, are you maybe trying to email directly?