Are you able to provide the event lines or MFA example? I've found in the past that fast loops can cause issues with extensions so the crashing may be the way in which the email is being processed.
Also are you needing to send and/or receive email? I did make an example of processing an imap mailbox without using the email extensions a while back by using the winsock extension. You could also do similar with SMTP (by using SMTP commands).