https://wpforo.com/community/?wpfs=504+Gateway+Time-out+-+The+server+didn%27t+respond+in+time

In most cases it is hosting related.

Hi Anonymous20,

Thanks for your reply, but to be more precise on the issue, we have two forums on our site :

- one forum is private and used by 17 persons : no 504 error in this forum when publishing a message, and a normal time to validate a new message.

- the other forum is opened to every users, around 2000 persons, and everyone has subscribed to every message, so many notifications emails are send through POST SMTP each time a new message is published.
It is in this forum that we have this issue, with a VERY long time after you validate the new message.

That's what make me say that it could perhaps be related to the time needed to send all these notification emails.

In other words, at what time does the SMTP sending process give back hand to Wpforo? And this lapse of time, if too long, could it be counted as a "timeout" by the system, and generate this error?

That make some sense, but even so it is a hosting problem. A slow "way" to send emails. Smtp sends directly the emails or routes them to a mail server ?

I thought that the time necessary for POST SMTP to treat a large quantity of emails and send them to the SMTP server could be a part of the problem, and so that this problem could find a solution locally (perhaps a SMTP plugin more efficient or a CRON service, or a parameter to change in WPForo), am I wrong?

Concerning the SMTP route, I don't know, I suppose I should ask my provider (INFOMANIAK)...

You talk about a "slow way", do you know faster ways to send this notification emails, that could solve my issue?

And by the way, how is THIS forum managed concerning the sending of these emails?