My email provider is going out of business and I need to switch MX records to a new one but don't want to lose email for 8+ hours as it often takes with these guys.
Is there anyway to do a quick transition without losing a ton of emails?
My company gets 400+ sales/support inquiries daily.
Thank you.
Go set your MX domain's TTL record to 60 seconds a day or so before the change.
Then, when you change, it will take a MAXIMUM of 60 seconds (and usually faster) to swap. 60 seconds is a common minimum for your DNS provider, but some may let you go even lower.
Just set it back to a few hours once you are done to ensure it is cached adequately as this both reduces load on the global DNS infrastructure, and increases the speed for end users.
Edit: It's also worth pointing out that the nature of SMTP is such that you will never "lose" emails. It's just that during the TTL timeout period, you will gradually transition from one provider to the other, so if your TTL is 8 hours, some messages may be delivered to the old server for 8 hours, while the rest go to the new server.
Note, this is probably better in the "Networking" forum.