How To - Configure email alert to use multiple SMTP relay servers
Within the scope of monitoring connectivity, use of email alerts rather than dial-out pager alerts can present various problems. The main problem encountered would be when your primary SMTP relay host is down - how do you send email message alerts?
In such a case, you will want to use your secondary SMTP relay if the primary SMTP server is unavailable.
IPSentry provides a simple method to accomplish this task.
Enter multiple SMTP Server addresses in the SMTP Server: field separating each address with a semi-colon (;) and a space.
Example: 10.1.1.1; 10.2.2.2; 10.2.2.3
Using this specification tells IPSentry to send all email through the server residing at 10.1.1.1. If however the email notification fails on this server, IPSentry would try 10.2.2.2. Once again, if a failure occurs on that server, it will attempt 10.2.2.3, and so-on until all possible SMTP relay servers have been tried.