Action: Exchange Online - Modify TTL setting to reduce email delay When people outside of your organization send you email, ...

Action: Exchange Online - Modify TTL setting to reduce email delay   When people outside of your organization send you email, their email systems don't double-check where to send that email every time. Instead, their systems save the location of your email system based on a setting in your DNS server known as a time-to-live (TTL). If you change the location of your email system before the TTL expires, the sender's email system tries to send email to the old location before figuring out that the location changed. This can result in a mail delivery delay. Your Office 365 mail users can experience this delay after moving to Office 365. One way to avoid this is to lower the TTL that your DNS server gives to servers outside of your organization. This will make the other organizations refresh the location of your email system more often. It's common to drop the TTL setting to a value of five minutes (300 seconds).  You configure your TTL value in the place you configure your MX DNS record. To learn how to modify the TTL setting, see Add MX record to route email.