Sendmail works and is maintained, so of course it's still actually used. That said, if you needed to get a message between two dissimilar messaging systems, th

Sendmail works and is maintained, so of course it's still actually used. That said, if you needed to get a message between two dissimilar messaging systems, then sendmail really shined. I don't mean "between gmail and outlook", I mean really different messaging systems. Like between SMTP and DECNet: no problems. UUCP connected MUA to a IBM CM/VMS PROFS user? We can make that work. AOL or Compuserv email address to Banyan Vines X.400? Why not. Now, it ranged from "this sucks" to "I will seek the peace of death once I figure this out" to actually get that stuff working reliably, but what you needed do it is in there. This is something that was very common for an MTA to need to do 30-40+ years ago. That was about the last time sendmail had a use case where it was genuinely superior to other offerings. Edit: VM/CMS, not CM/VMS.