When you look at the full headers of the email received, having sent it without the -r option, double check what the originating domain info looks like.
Then try with -r set to the same full qualified originating email address. That way mail doesn't have to figure out what domain to add to the abcd. If that works then somehow mail is not appending you originating domain address the way you want, and perhaps the target mail handler at cvut.cz is really complaining about the sender, and not the recipient. (I am not any kind of expert at this -- just wondering.) Austin On Sat, 30 Jan 2021, Rudolf Sykora wrote: > Dear list, > > > I tried to use the -r option with the mail program, but whenever I use > the option I get a error like this: > > > odin$ mail -r abcd -s abcd rudolf.syk...@cvut.cz > a > EOT > odin$ sendmail: command failed: 550 Invalid recipient: <rudolf.syk...@cvut.cz> > > > odin$ mail -s abcd rudolf.syk...@cvut.cz > sdas > EOT > odin$ > > > can anybody help me understand why? > > > Thanks > Ruda > >
