Solved

Email bounce backs

Posted on 2014-11-14
2
176 Views
Last Modified: 2014-11-24
Hi all,

We recently migrated to Office 365. Using Mimecast as a failover. We hit problems with DNS when 123-Reg MX record dropped. Re-instated the MX record but still getting random bounce backs from clients. Deleted cached email addresses but still getting host not found. Suspect that it is a local DNS issue. WHat is the standard TTL on DNS records for MX records.

Thanks
0
Comment
Question by:ncomper
2 Comments
 
LVL 13

Accepted Solution

by:
Andy M earned 500 total points
ID: 40442418
DNS records can typically take anything from 24-48 hours to update so if the MX record was lost you may need to wait upto 2 days for it to propagate to external sending systems.

This said I've seen some domain hosts set so the records have a TTL of 1 week!

If you go to network-tools.com, punch in your domain and look at the dns records you can see the expiry set on the SOA record which will give you an idea of the TTL.

Are the bouncebacks happening when you send an email to a third party or when they send to you? What does the bounceback say?

If the emails were working fine before the MX records went and nothing has changed since aside from the MX been reinstated it sounds like it's just dns records waiting to update.
0
 
LVL 5

Author Closing Comment

by:ncomper
ID: 40461647
Thanks for the feedback  it was a mixture of replication AND legacy MX records that should not have been left active. 3-4 days on it all settled down
0

Featured Post

Netscaler Common Configuration How To guides

If you use NetScaler you will want to see these guides. The NetScaler How To Guides show administrators how to get NetScaler up and configured by providing instructions for common scenarios and some not so common ones.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Not sure what the best email signature size is? Are you worried about email signature image size? Follow this best practice guide.
Is your Office 365 signature not working the way you want it to? Are signature updates taking up too much of your time? Let's run through the most common problems that an IT administrator can encounter when dealing with Office 365 email signatures.
This is Part 3 in a 3-part series on Experts Exchange to discuss error handling in VBA code written for Excel. Part 1 of this series discussed basic error handling code using VBA. http://www.experts-exchange.com/videos/1478/Excel-Error-Handlin…
To add imagery to an HTML email signature, you have two options available to you. You can either add a logo/image by embedding it directly into the signature or hosting it externally and linking to it. The vast majority of email clients display l…

770 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question