Verifying Domain with Mailchimp

They are both doing the exact same thing, regardless of the TTL.

The TTL only suggests how long that the other end should remember (e.g. “cache”) the DNS response for.

So which one you delete shouldn’t matter.

To comply with Mailchimp weird way of doing business, you might need to delete the one that has the AUTO TTL.

To elaborate on the “weird way of doing business”, I suggest you read the phrase I mentioned just ~ 23 minutes before your thread, and especially the last two lines / sections.

TL;DR: If Malchimp requires the use of “p=none;”, I would look at another provider for your email deliveries.

In addition, … in regards to input:

I don’t know your affiliation with SendGrid (as mentioned in your records), and whether you’re trying to leave them and if that would be your reason to choose Mailchimp, or it is going to be a mix of using them both, or similar.

However, in regards to deliverability through SendGrid, I wouldn’t be expect anything at all.

SendGrid has for more than a decade turned the blind eye to spam, phishing and malware egressing from their network, and never done anything to e.g. terminate bad customers.

The Swiss Government Computer Emergency Response Team did for example comment the role of those email provides, with a very specific mention of SendGrid over here:

“SpamGrid”, as it is referred to in various email communities, wouldn’t be a provider I put my faith in…