SAP to send external mails

How to configure SAP to send mails.

After reading lots of threads related to this subject I found that most of the issues can be resolved by reviewing a few simple steps.

First you need to read the basic configuration found in the SMTP guide available in help.sap.com, If after that you still have trouble here is a few tips.

1.  Always check that the port (usually port 25) is open and you can reach your SMTP server. You can do this by simply telnet the port if the port fail to reply please contact your network team.
   1. Open a command prompt
   2. Telnet
2. Check that the IP Address of you SAP Server is maintained on the SMTP Relay Agent of your SMTP Server. Basically SMTP server require authentication by adding the IP Address of your server in the SMTP Relay Agent all the requests coming from your SAP system will be "trusted".
3. Make sure that the E-mail Address and the Communication Method are maintained in SU01, this is a basic requirement to send an e-mail and without it your mail simply won't be sent.

Also please refer to following SAP Notes,
Note 455140 - Configuration of e-mail, fax, paging or SMS using SMTP
Note 455127 - E-mail (SMTP) in different SAP releases