Sendmail unable to find users?
 

Hello,

I was wondering if any of the linux/sendmail gurus out there could help me figure out this problem.

I decided to set up linux on a spare computer I have lying around. I am trying to set it up as a mail/web server, but have run into some basic configuration problems mostly related to sendmail (at least I think).

Anyways, the problem is this:

Lets say I have these three users:
1. root (standard)
2. FLast (Firstname Lastname --> FLast)
3. test (created for testing)

FLast and test can send mail to root. root receives this mail.

root can send mail to test. test receives this mail.
root cannot send mail to FLast. Sendmail returns an error.

at a shell prompt, this is what is returned using sendmail -bv:
> sendmail -bv test
test... deliverable: mailer local, user test
> sendmail -bv FLast
FLast... User unknown
> sendmail -bv root
root... deliverable: mailer local, user root


Does anyone have any idea why mail would be deliverable to test but not FLast? Is this an issue with having caps in the user name?

Both these users were configured in the exact same manner using the exact same settings.

System Specifics
Distribution: Redhat 7.3
Sendmail Version: 8.11.6-15 (included and configured by Redhat)

If needed, I can post my sendmail.mc file.


Any help would be very greatly appreciated, thanks!

Sendmail, by default, will convert upper-case usernames to lower-case prior to delivery, in order to allow "case-insensitivity" in email addresses.

If you wish to keep your upper-case usernames, you will need to change the Mlocal line in your sendmail.cf. Here's an example. Change:

Mlocal, P=/usr/bin/procmail, F=lsDFMAw5.....

to:

Mlocal, P=/usr/bin/procmail, F=lsDFMAw5u...

The addition of the lowercase "u" option tells sendmail to preserver upper-case usernames when attempting local delivery. Or, you could just use lower-case usernames ;)

Thanks for the help!

I think I'll go with all lower case user names. That probably will make it a lot easier if people try to send e-mail to FLast@mydomainname.com as most people don't check case sensitivity in names. :)

Thanks again! Now I can start setting up qpopper ;)