replace MTA with something not email related

What I try to achieve is to send all my server logs, errors, crontab outputs etc. with something like telegram or signal. I am locking for a MTA with can handle a different backend and is still compatible with the overall Linux MTA concept. So **without** fiddling with scripts and crontabs I would like all output, which would be transfered by mail to be transfered by a custom backend. Is there a way to change the MTA backend? What I found so far is ntfy , but it's just a script to set different notification backends, I think there is a missing puzzle piece between the script and a proper MTA. Thanks for the input