So this morning I tried adding a new email alias to an email user and got the error “invalid malias format”.
After some trial and error, it seems that the maximum length of an email alias is 30 characters. Is there a good reason for doing so? This particular user would like an alias 32 characters long.
That limit is a maximum of 64 characters (octets) in the “local part” (before the “@”) and a maximum of 255 characters (octets) in the domain part (after the “@”) for a total length of 320 characters . However, there is a restriction in RFC 2821 on the length of an address in MAIL and RCPT commands of 254 characters.