Apple Mail Keeps Going Offline on a Mac: What to Check First
Apple Mail keeps going offline even though websites still work? Check the account message, webmail, password, storage and server settings in the right order.
This article is about Apple’s Mail app repeatedly showing an account as offline. It is not about Outlook not syncing, Microsoft 365 licensing or choosing between Apple Mail and Outlook.
If websites still open but Mail goes offline, read the message beside the account before changing anything. “Unable to connect”, “login failed” and “password rejected” are different problems.
Confirm the internet really works
Open Safari and load a new website. If that also fails, fix the internet connection first.
If the internet works, quit Mail, wait a moment and open it again. A short outage at the email provider can take an account offline even when the Mac and Wi-Fi are fine.
Read the account message
Mail may report that the network is offline, it cannot connect to the server, login failed or the password was rejected.
A network message can be caused by a VPN or security app that monitors connections. A login message usually points to the password, account approval or provider. Do not keep entering a password if the message never changes.
Test the mailbox in a web browser
Sign in to the email provider’s webmail using Safari. Send a message to yourself and reply to it.
If webmail also fails, the problem is with the account, password, service or storage rather than the Mail app. Fix that first. If webmail works, the account itself is active and you can focus on the Mac.
Check the account is not full
Some email providers stop accepting new messages when the mailbox reaches its storage limit. In Mail, Control-click the account mailbox in the sidebar and choose Get Account Info to review its use.
If the provider’s webmail says the account is full, remove messages you no longer need or increase the provider’s storage. Emptying Bin or Deleted Items may be necessary before the space is released.
Look for a password or account approval problem
If you recently changed the password, Mail may still hold an old sign-in. Open System Settings, Internet Accounts, select the account and follow any request to sign in again.
Some providers also pause access until new terms, security questions or two-step verification are completed in the browser. Finish those prompts before testing Mail again.
Leave server settings automatic unless told otherwise
In Mail, choose Mail, Settings, Accounts, select the account and open Server Settings. For most current services, automatic settings are the safest choice.
Only change the incoming or outgoing server name, port, authentication or security setting when the email provider has given you the exact current values. Guessing can turn a receiving problem into both a sending and receiving problem.
Remove and re-add the account only at the end
If webmail works, the password is accepted, storage is available and the settings still will not recover, removing and re-adding the account can rebuild the connection.
Before doing that, check for mailboxes under On My Mac. Those messages may exist only on this Mac and are not restored by signing in again. Make a backup before removing anything you are unsure about.
If the account keeps dropping offline
A repeated problem can point to a VPN, network filter, damaged account setup or an email service that no longer accepts the old sign-in method. Test on another internet connection and note the exact error message and time.
For Microsoft 365 users, our guide to Outlook not syncing on a Mac covers Outlook rather than Apple Mail. Our guide to choosing an email app for Microsoft 365 explains when Apple Mail is a sensible fit.
Need a hand?
For home email support, see Microsoft Office & Email for Home. Businesses can see Microsoft 365 & Email, or contact Your Mac Tech.
