One MX record
Google documents a single MX record for Workspace: smtp.google.com at priority 1. Accounts that began before 2023 may have older values starting aspmx, which Google says still work if mail is flowing. Google tells you to remove other MX records because leftover or incorrect entries may break email, and says a new record may take up to 72 hours to be recognised. When you leave Google, the same rule applies in reverse: the new provider's record should replace Google's, not sit beside it.
Labels are folders for IMAP
Gmail has labels, and Google says it treats labels as folders for the purposes of IMAP, so tools that read mail over IMAP see each label as a folder. System labels have names starting [Gmail]. One message can carry several labels. This matters in any migration out of Gmail, because folder-based mailboxes expect a message in one place. Plan the label handling before the first copy and test it on one pilot mailbox.
Forwarding, redirecting and routing are different
Google describes forwarding as altering the original message and carrying its history, while redirecting leaves the content untouched so the message looks as if it came straight from the sender. Routing is the organisation-level set of options such as dual delivery and catch-all. Google also notes that if a forwarding server is not in your SPF record, SPF may fail, and if it changes the body, DKIM may fail, with the message possibly rejected or marked as spam.
Sender rules for mail to Gmail
Google's sender guidelines say that from 1 February 2024 every sender to Gmail needs SPF or DKIM, valid reverse DNS and TLS, and a spam rate under 0.3 per cent. Bulk senders, those sending more than 5,000 messages a day to Gmail, must set up both SPF and DKIM and publish DMARC. A forwarded message from your domain is judged by these rules at its destination, which is why forwarding to a Gmail address can fail even when your own mail is fine.
Where our jobs fit
Each is a published test price, not yet tested with buyers, payable after sign-off. The Google Workspace to Microsoft 365 mailbox move is £395, the forwarding repair £165, the mail routing repair £175 and the sender-authentication job £195. Calendars, contacts, Drive files and Groups are outside the fixed mailbox move. We never need your administrator password by ordinary email.
Sources and limits
- Google Workspace: set up MX records Checked 2026-10-11.
- Google Workspace uses a single MX record, smtp.google.com at priority 1, with older aspmx values still working, and says to remove other MX records.
- Google: Gmail IMAP extensions Checked 2026-10-11.
- Gmail treats labels as folders for the purposes of IMAP.
- Google Workspace: forwarding, redirecting and routing Checked 2026-10-11.
- Forwarding alters the original message while redirecting does not, and routing features include dual delivery and catch-all.
- Google: Email sender guidelines Checked 2026-10-11.
- From 1 February 2024 all senders to Gmail need SPF or DKIM, valid DNS and TLS; bulk senders need more, including DMARC.