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Saty_Attota_201's avatar
Saty_Attota_201
Icon for Nimbostratus rankNimbostratus
Jul 02, 2018

SMTP mail - getting error 550 5.7.1 Unable to relay for

I did set up mailhub. Could see entry in /etc/ssmtp/ssmtp.conf as expected.

 

Created SMTP configuration from System -> Device -> SMTP

 

Later I issued the following commands:

 

modify /sys outbound-smtp mailhub xxxxx.sierracollege.edu:25 save /sys config

 

I tested with following mail command: echo "Test message" | mail -vs "Test message" user@sierracollege.edu

 

But I am getting error. I could telnet to mail server. Here is the log

 

echo "Test message" | mail -vs "Test message" user@sierracollege.edu [<-] 220 xxxxx.sierracollege.edu Microsoft ESMTP MAIL Service, Version: 8.5.9600.16384 ready at Mon, 2 Jul 2018 11:34:45 -0700 [->] HELO f5-xxxxxxx.sierracollege.edu [<-] 250 xxxxx.sierracollege.edu Hello [10.16.0.5] [->] MAIL FROM: [<-] 250 2.1.0 root@f5-xxxxxxx.sierracollege.edu....Sender OK [->] RCPT TO: [<-] 550 5.7.1 Unable to relay for user@sierracollege.edu send-mail: RCPT TO: (550 5.7.1 Unable to relay for user@sierracollege.edu)

 

Can someone suggest how to resolve this problem.

 

Thanks in advance

 

application delivery
BIG-IP
Super-NetOps
TMOS
  • Saty_Attota's avatar
    Saty_Attota
    Icon for Nimbostratus rankNimbostratus
    Jul 02, 2018

    Here is additional comment.

     

    telnet host 25 is successful with return code 220

     

    helo testing returned succeful code 250

     

  • Saty_Attota's avatar
    Saty_Attota
    Icon for Nimbostratus rankNimbostratus
    Jul 02, 2018

    Forgot to mention that I added f5 ip address in relay list too. No problem with firewalls

     

  • Chase_Abbott's avatar
    Chase_Abbott
    Icon for Employee rankEmployee
    Jul 02, 2018

    You should be able to telnet from the BIGP-IP to Exchange and send an email. If that cannot happen, Exchange still needs further configuration. In this case, you're using BIG-IP like any telnet client.

     

    1. Verify the IP you specified to relay IS the actual IP being used. If you setup automap versus SNAT pool. BIG-IP can have many sending IP addresses so SMTP/Transport Agent logs will verify (or tcpdump/wireshark the Exchange Transport/CAS box).
    2. Is requires authentication enabled for the receive connector? 550 5.71 can fail due to the receive connection auth settings.
    3. Is the sierracollege.edu setup as a receiving domain for this? The failure happened immediately after RCPT instead of completing the mail setup .

    You should be able to complete a basic SMTP handshake in any telnet client to validate this works. If that fails, you'll need to investigate the incoming receive connector, transport agent, and other Exchange related configs prior. Best step is to simplify the config to basic send/receive before introducing new configs and proxies.

     

    If you want, obfusicate and send along transport logs of the session.