Hi Admin! When you were writing this, did you consider the possibility of adding an alias and deprecating addresses with ~ and /? It seems stubborn to cling unto an rfc considering their informal nature. Please consider that it wasn't my software that had trouble parsing the addresses, it was my brain, I ignored the part before the / assuming it was a comment like the <> notation. Regards, Tomás. ---- En sáb, 25 jul 2020 19:22:10 -0300 <email@example.com> escribió ---- Hi Tomas! We received your email, but were unable to deliver it because the mailing list you wrote to was not found. The correct posting addresses are: ~username/mailto:firstname.lastname@example.org Or if your mail system has trouble sending to addresses with ~ or / in them, you can use: email@example.com If your mail system does not support our normal posting addresses, we would appreciate it if you wrote to your mail admin to ask them to fix their system. Our posting addresses are valid per RFC-5322. If you have any questions, please reply to this email to reach the mail admin. We apologise for the inconvenience.