I just installed osTicket v1.18.2. I do not have the php-IMAP module because it is not available as part of el9. What functionality, if any, is missing without the php-IMAP module?
diggy
The php-imap extension is no longer required and our system was updated to reflect as such as part of this commit. Small back story, we used to rely on native PHP IMAP functions (provided by the extension) to fetch mail. Since the introduction of Modern Email Authentication (ie. OAuth2) PHP said “Nope, sorry! We are done with this shit! Go use other packages like laminas-mail!”. I wish I saved the link to the comment/post as I can’t find it now. PHP themselves have even deprecated the imap extension and unbundled it from core since 8.4. Anyways, since they said they weren’t going to support it you either had to “roll-your-own” OAuth2 support or switch to a package that supports both IMAP and OAuth2 natively (like the recommended laminas-mail package). The good thing about laminas-mail is it doesn’t require the imap extension as it uses its own methods to fetch mail. It is however helpful in mime decoding messages as seen below:
php-imap
laminas-mail
Cheers.
The main function that I can think of would be email fetching/ticket creation. I don't use email fetching in my environment, so I don't know of all its functions.