My LimeSurvey Version is 2.52

After using Lime for a few years sending invitations under several office365 clients, it stopped working.
I get the generic "SMTP connect() failed. github.com/PHPMailer/PHPMailer/wiki/Troubleshooting ".
In the past few months it started sending only half of the batch (half received the above error and half went through) and about 2 weeks ago it stopped and all recipients get delivery error.
I tried gmail smtp client and it works fine.

Anyone has an idea what have changed in 365 that could cause that?

Thanks
 

Because Office 365 ask
Sender address == From address == ReturnPath address

Reason : no reason, just because microsoft doing shit.

Reason we have to create a plugin just for Microsoft : github.com/LimeSurvey/LimeSurvey/tree/ma...ins/mailSenderToFrom
(we work freely for microsoft sometimes).

Thank you very much Denis.
Sorry for my ignorance.. Is that a regular plugin, just need to add it to the plugins folder?

Arg … didn't see you use 2.52 … it's included in 5.X official version.

You can not update ? Your version have a lot of issue, and have major security issue too …

With a 2.52 : think best is to hack PHP code to set your own sender …

Thanks. Maybe I'ts time to update my version

Not just maybe. The 2.5x release was full of bugs from the beginning and there were almost daily updates due to this. Your 2.52 is one of the first releases of this branch and I could not imagine to use this in production. I never considered the 2.5x/2.7x branch as stable and therefore skipped directly from 2.06 to 3.x, which was far more stable from the beginning.

Your 2.52 should be from 2016 or something, so over 5 years of no bug fixes, security updates or general updates, for a software that might be used to collect personal data of respondents...

I think it is a really, really, really, really, REALLY - did I already mention "really"? - good idea to update.