> On Aug 27, 2019, at 10:10 PM, Eliza via Exim-users <[email protected]> > wrote: > > Is exim a multi-processes MTA,
No, Exim is largely monolithic, with the same process accepting the inbound message and delivering it (modulo some messages being queued for later delivery). > While postfix is a threads powered MTA? No, Postfix is not multi-threaded. Rather different stages of message processing are handled by separate services: http://www.postfix.org/OVERVIEW.html So the key architectural difference is that Postfix is not a single monolithic program, but a collection of programs that handle various aspects of message processing. Monolithic programs are more difficult to secure. -- Postfix developer perspective below: The most significant user-visible difference is that Postfix has a queue-manager, which implements advanced concurrency/fairness controls. On the other hand, Postfix has fewer built-in content inspection features, relying instead on external milters and (SMTP or just unix pipe) content filters. Postfix is optimized for security, performance and ease of configuration at the cost of a more spartan set of built-in content inspection features. I'll leave to Exim developers to highlight key aspects of the Exim architecture and user-visible features. -- Viktor. -- ## List details at https://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/
