Email not getting through to our domain after network downtime???

[hayabusaukuk]

Our office internet connection was offline for a whole weekend recently and since then some email has bouncing back from some domains, i think their email system is still flagging us as being down.

This seems to be from people who tried to email us when our connection was down.

How can i force everyone to know we ae back up and running!!???

 

[goombawaho]

Generally e-mail doesn't work that way. In other words, I try to send to you and your mx record ip address doesn't respond (for whatever reason). Now, one of two things can happen - my mail server/client can immediately give up and give me an undeliverable message or it can schedule periodic retries.

If people that have e-mailed you have a server that retries, it should succeed at a point after your internet connection came back up. Verify that you can send a brand new message to your domain from another domain (yahoo/gmail). This will prove your system is capable of receiving mail.

Then, for the people that are unable to send to you that had tried while your server was down, do the following. Walk someone at one of those places try to send from the command line using the following procedure and your mx record ip address.

http://www.yuki-onna.co.uk/email/smtp.html

scroll down to TELNET - there a nice picture

http://www.msexchange.org/articles/Sending-Email-without-Client.html

 

[lhuegele]

Here's what we did to prevent lost emails if our Internet was down:

- We found a 3rd party company to host a second backup SMTP server for our company, off-site.
- We added the second MX record into our external DNS that pointed to the backup SMTP server.
- We configured the backup SMTP server to hold ALL incoming mail if our primary server was ever unreachable. The retry timeout was HUGE so even if we were down for 7 days, that backup SMTP server will still hold on to all our incoming messages until our primary was back up.

Now, of someone tries to send us and email and our primary email server is down (for whatever reason), their email server automatically routes that email to our backup SMTP server. The backup SMTP server (a relay server) then collects all this inbound email. When our primary server is back online, the backup SMTP server then delivers all that email to our primary email server so nothing inbound is ever lost.

We have noticed some email servers still sending inbound emails through our backup SMTP server even after our primary is back up, but they usually figure out the primary is back up within 24-48 hours tops.

Good luck,