Changing TTL on MX from 5 to 3600 breaks email!

Email forwarding to GSuite has been working fine since I set it up on Netlify weeks ago. However I thought it would be a good idea to increase the TTL on the MX and TXT records from my set up value of 5 seconds to the default value of 3600.

I created a new matching record for each entry with the new TTL of 3600 and then deleted the old entry. I quadruple checked everything was exactly the same as a screenshot of my original settings (attached).

The problem was I was then unable to receive email although I could still send them. 12 hours later and I could still not receive any emails.

To try and fix it I then changed back to the TTL of 5. That was 5 hours ago and I am still unable to receive emails.

How is this possible and what should I do to resolve?

FWIW I managed fix the issue.

I tried a number of fixes but think that deleting all the MX records and then reentering them was key. When I updated previously I reentered the new copy before deleting the old copy and that seemed to confuse things.

Glad to hear you got things sorted out, Joey! That is an odd experience and one I’ll try to reproduce and get a bug filed on for us.

I seem to have been caught out by this bug. My email has now been down for about 24 hours.

Most DNS records allow you to edit the TTL - this is probably why we both approached it in similar ways as ‘deleting’ a record is seen as fairly destructive by most people.

Hopefully Netlify will fix this as it’s obviously a bug in the system and makes for a pretty poor experience if you’re relying on DNS

Hi, @glenpike, are you sure the issue is Netlify DNS?

I think I found the DNS zones for Netlify DNS associated with your team (but it would be helpful to confirm I’m looking that the right configurations.

One zone is working correctly (the MX records respond as configured). The other zone is configured at Netlify but not enabled at the domain registrar so it isn’t working.

Would you please confirm which records aren’t working when you test?

Hi,

Aah, please don’t get my team account confused with my personal account, (that’s another bugbear of mine, I can’t separate work and personal stuff as it’s all on the same GH account but different org’s)

I have moved my nameservers since posting here, so DNS records may still be configured locally, but they’re currently unused.

The ones I could not change were the MX records for glenpike.co.uk, so I created 2 new ones with the same server but a 60 second TTL, then deleted the originals.

My records on the other nameserver are currently working now.

Glad to hear you found a solution! :+1:

We do have an open feature request to be able to edit exiting Netlify DNS records. This topic and the feature request are cross-linked for tracking and follow-up. We’ll post here in this topic if/when that becomes a reality.

In the meantime, creating new records and then deleting the previous ones would be our recommended workaround.