mailbox name can only contain alphanumerals and dot

[ccfu]

It would be good to know whether this is a bug as I assume or a deliberate feature / limitation of the mailserver implementation.

[nebulon]

Pulling in @girish since this sounds like a bug or maybe related to some mail server quirk.

[girish]

Internally, the mail server uses LDAP for authentication and getting configuration information. In LDAP, the _ is not a printable character - https://datatracker.ietf.org/doc/html/rfc2252#section-6.29 and has to be escaped. We ran into some issues because of a combination of LDAP protocol and the ldapjs (the node module we use). Apps also behave randomly if you have _ but this is in usernames though. For example, _ in the openvpn app causes trouble. This could have changed though, since we haven't tested this in many years now.

Is it common to have underscore in email addresses? I haven't seen them in forever. Please also consider that such characters might be hard to type in certain keyboards and might also look like a different character in other languages. FWIW, gmail does not allow them.

See also: https://support.google.com/mail/thread/2835604/i-want-to-create-my-account-with-underscore-sign?hl=en

[robi]

@girish they are common, esp in the crowded free email hosting space. Yahoo got it right, Google didn't, so instead of fixing it all they disabled it on the front end.

[girish]

@robi yeah, i stand corrected. Looking into my address book, I have a bunch of hotmail and yahoo addresses with underscores in them.

[girish]

I have fixed this in next release - https://git.cloudron.io/cloudron/box/-/commit/15d0dd93f45fe74c76a62637faabf9bfdd5efbfe . Just the one liner change. Not fixing usernames though since that is more complicated.

[ccfu]

@girish

Thanks for fixing this.

Btw. Google does accept underscores on business accounts (thats where we used them in some aliases), but as you pointed out not on Freemail accounts. In fact Gmail doesn't even allow hyphens.

[girish]

@ccfu ah good to know that the business gmail allows them.

[mehdi]

@girish There seems to me that there is an error in the commit in question : in the regex, you have .-_, which means "the range between the char" . and the char _, and not "these 3 chars". You probably want to escape the - with \, or it will allow lots of other unwanted characters like ], = or ^

[girish]

@mehdi good catch, will fix!