On 04/30/2016 12:22 PM, Gordon Messmer wrote:> On 04/30/2016 11:28 AM, Alice Wonder wrote: >> Is there any advice on characters to allow in usernames? > ... >> I don't think a whitelist alphabet is best approach because of people >> with names that are not spelled with Latin characters. >> >> Is there an existing blacklist of characters that technically legal >> but are generally avoided in e-mail addresses? > > The RFC uses a list of allowed characters, and so must you.For e-mail sent to people, yes. But for what usernames are allowed when creating an account, I don't see why blacklisting characters that are not allowed in a username is a standards problem.
------------ Original Message ------------> Date: Saturday, April 30, 2016 12:44:52 -0700 > From: Alice Wonder <alice at domblogger.net> > > On 04/30/2016 12:22 PM, Gordon Messmer wrote: >> On 04/30/2016 11:28 AM, Alice Wonder wrote: >>> Is there any advice on characters to allow in usernames? >> ... >>> I don't think a whitelist alphabet is best approach because of >>> people with names that are not spelled with Latin characters. >>> >>> Is there an existing blacklist of characters that technically >>> legal but are generally avoided in e-mail addresses? >> >> The RFC uses a list of allowed characters, and so must you. > > For e-mail sent to people, yes. > > But for what usernames are allowed when creating an account, I > don't see why blacklisting characters that are not allowed in a > username is a standards problem.You can set any rules you want for what your local users can use for their accounts -- within the constraints of the mail RFCs. You just have to accept mail with and allow your users to send to any RFC compliant email address.
On Sat, Apr 30, 2016 at 12:44 PM, Alice Wonder <alice at domblogger.net> wrote:> > For e-mail sent to people, yes. > > But for what usernames are allowed when creating an account, I don't see why > blacklisting characters that are not allowed in a username is a standards > problem.That's not how the RFC rules are defined. But, rather than argue that point at length, I'd point out that Open Group standards for usernames are simple and will comply with the SMTP RFCs: http://pubs.opengroup.org/onlinepubs/000095399/basedefs/xbd_chap03.html#tag_03_426 That is, [A-Za-z0-9._][A-Za-z0-9._-]
On 04/30/2016 08:56 PM, Gordon Messmer wrote:> On Sat, Apr 30, 2016 at 12:44 PM, Alice Wonder <alice at domblogger.net> wrote: >> >> For e-mail sent to people, yes. >> >> But for what usernames are allowed when creating an account, I don't see why >> blacklisting characters that are not allowed in a username is a standards >> problem. > > > That's not how the RFC rules are defined. But, rather than argue that > point at length, I'd point out that Open Group standards for usernames > are simple and will comply with the SMTP RFCs: > http://pubs.opengroup.org/onlinepubs/000095399/basedefs/xbd_chap03.html#tag_03_426 > > That is, [A-Za-z0-9._][A-Za-z0-9._-] > _______________________________________________ > CentOS mailing list > CentOS at centos.org > https://lists.centos.org/mailman/listinfo/centos >I think there is a mis-understanding. All I was looking for was if there was a common set of characters typically blasted from new usernames *on the domain being set up* I have no desire to refuse delivery to any valid e-mail address. For example, avoiding spaces in usernames for addresses on the system is handy because it avoids bugs where the path to the mailbox on the filesystem isn't properly quoted. So user names on the system won't be allowed to have spaces even though they are legal when within quotes or escaped. That's all I was looking for, was experience on what legal characters to avoid allowing users to have for the mailbox portion of their e-mail address, the username. Of course I have no desire to restrict who they can send to if it is a legal address.