Ubuntu – Plain-text login with sendmail and SASL, Ubuntu 10.04

saslsendmailsmarthostUbuntuubuntu-10.04

I'm trying to configure sendmail with a smarthost. I mostly followed this guide (although I understand it is written for Scalix).

SMTP server uses plain-text authentication. However, when sendmail tries to relay an email, I see this error in sendmail.log:

May 17 01:55:28 myhost sm-mta[12153]: STARTTLS=client, relay=smtp.myserver.com., version=TLSv1/SSLv3, verify=FAIL, cipher=DHE-RSA-AES256-SHA, bits=256/256
May 17 01:55:28 myhost sm-mta[12153]: s4GKkZNt010225: AUTH=client, available mechanisms do not fulfill requirements
May 17 01:55:28 myhost sm-mta[12153]: AUTH=client, relay=smtp.myserver.com., temporary failure, connection abort
May 17 01:55:28 myhost sm-mta[12153]: s4GKkZNt010225: to=<my@email>, delay=01:08:53, xdelay=00:00:01, mailer=relay, pri=840427, relay=smtp.myserver.com.

Why does it try to use TLS?

After some googling, I understand it has something to do with SASL library. I saw several advices on installing cyrus-sasl-plain package, but it is not available in Ubuntu 10.04.

What should I do?

Best Answer

OK, this solved my problem:

sudo apt-get install libsasl2-modules

This installed several modules, including liblogin and libplain and now everything works fine.

Related Solutions

Sendmail: SMTP host name lookup failure

I'm going out on a bit of a limb here, but I think the problem is your remote host ...

getmxrr(smtp-server.nycap.rr.com, droplocalhost=1)
getmxrr: res_search(smtp-server.nycap.rr.com) failed (errno=110, h_errno=2)
<zeno@biyg.net>... Deferred: Name server: smtp-server.nycap.rr.com: host name lookup failure

It looks like res_search is the culprit here and what it's searching for (smtp-server.nycap.rr.com) is producing the error. According to netdb.h (I think) that error is either non-authoritative host or SRVFAIL.

Checking dns, it does look like something's wrong with that host (please forgive the use of nslookup) :

Non-authoritative answer:
Name:   smtp-server.nycap.rr.com
Address: 75.180.132.33

nslookup
> set q=ptr
> 75.180.132.33

Non-authoritative answer:
33.132.180.75.in-addr.arpa      name = cdptpa-omtalb.mail.rr.com.

I want to say it looks like a forward/reverse mismatch, but I could be wrong. It could just be one bad entry in their mailcluster. I'm thinking the reason that it works in the debug mode is that ruleset 3 is skipped and part of that ruleset is doing reverse lookups on the destination mailserver.

You might be able to solve this with a mailertable, that would go a ways towards fingering DNS info as the culprit. Take a look at this -- Solving hostname lookup failures in sendmail

Centos – sendmail & sasl auth on CentOS 6

Your sendmail.mc looks ok. Apart from stopping and starting sendmail again (which I would guess you have already done). I would look at the actual configuration file which would be called sendmail.cf.

Make sure you see the lines:

C{TrustAuthMech}DIGEST-MD5 CRAM-MD5 LOGIN PLAIN

and

# list of authentication mechanisms
O AuthMechanisms=DIGEST-MD5 CRAM-MD5 LOGIN PLAIN

If LOGIN PLAIN is not there then your 'make' is not generating the .cf file from the .mc file.

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