Error 500 on Wp-admin Panel Due To Plugin

Site was working fine till just a few days ago when we couldn’t get to the wp-admin panel (showing error 500). We contacted our hosting and they said they deactivated Postie and the issue was resolved.

However, we need this plugin to work and it has been working for us for five years. The only other info we have is that they were saying before that it might have been a PHP memory limit issue and we noticed there was a plugin update in the last few days.

Any help would be appreciated

Thanks