If you’re running Mautic and jumped onto PHP 8.5 early, you might have hit a snag during installation or updates: the dreaded “ext-imap missing” error when using Composer. This one popped up recently in the Mautic community, and it’s worth unpacking for anyone trying to keep their Mautic setup smooth and up-to-date.
Here’s the deal. PHP 8.5 officially removes the ext-imap extension. This extension has been Mautic’s requirement for a while—especially for parts of core-lib which rely on it. So when you try to install or update Mautic with PHP 8.5, Composer throws an error because it can’t find this extension on your system. The quick error looks like:
mautic/core-lib 7.2.1 requires ext-imap * → it is missing from your system.
This forces two rough workarounds people have been using: either downgrade to PHP 8.4 temporarily or run Composer with an ignore errors flag. Neither is great long term.
Digging around the Mautic GitHub and community chatter, there isn’t an official fix yet. The core-lib package still lists ext-imap as a hard requirement, which doesn’t reflect PHP 8.5’s removal of that extension. A popular suggestion is to use the ext-imap-polyfill package, which acts as a drop-in replacement for the removed functions. But that’s an additional dependency and needs core-lib to relax its requirement constraints—or for Mautic updates that address PHP 8.5 compatibility.
The practical takeaway? If you want to keep using PHP 8.5 with Mautic right now, you’re stuck with either:
- Switching back to PHP 8.4 for installation and updates, then upgrading cautiously.
- Using Composer’s ignore platform requirements flag, knowing you might face runtime issues if IMAP functionality is critical.
For the everyday marketer running Mautic, this means: PHP 8.5 isn’t quite ready for prime time yet unless you’re comfortable with workarounds or development tweaks. The Mautic team and community will likely update packages soon to handle this, but until then, stick with PHP 8.4 to keep your installs and updates clean.
Want the full community discussion and to track any updates on this? Check out the original forum thread here.
And if dealing with these kinds of PHP and dependency headaches isn’t your cup of tea, Mailertizer runs Mautic for you—on solid, tested environments so you can focus on marketing, not server quirks.
