Although the Apple Mail email client was designed to make it easier for macOS users to work with email, sometimes it’s the other way around. Some users encounter a problem in which the Mail application cannot send or accept new mail that because protocol cannot send message using the server, although old messages are displayed in the client. Sometimes a problem affects only sending or only receiving mail. Although Mail’s behavior can be confusing, the problem is usually pretty simple if your mail stuck in outbox on your Mac.

Identify the Problem

First of all, you need to understand what is the problem of sending and receiving mail:

  • To do this, open Mail app;
  • Open the “Window” menu;
  • Select “Connection Doctor”.
How to Fix if Apple Mail not Sending?
  • Press “Show Detail” for more information.
How to Fix if Apple Mail not Sending?

For each account, connections are made to two servers: an incoming mail server (usually using a POP3 or IMAP connection for this) and an outgoing mail server (via SMTP). As a result of the steps described above, your email client will check them all and show which connections have been successfully established and which problems have occurred. If you have several mail accounts (and especially if you use different mail services) and as a result of the check it turned out that they are all inaccessible, most likely the problem is in the Mail settings or Internet connection.

Read more: How Does Mail Drop Work?

If you have only one mail account (or a problem with only one), there are several options. As mentioned above, two connections are established for each account. If the problem occurred with only one of them (for example, only with SMTP), then most likely the case is in the Mail settings. If both are unavailable, the reason may be both in the settings of the mail client and on the side of the mail server. It is worth checking whether there are any problems on other devices, and also try to log into the web interface of your email account. It is also worth contacting your email technical support and clarifying whether your account is active, whether the settings for connecting to servers have changed, and whether there are any problems at the moment.

Disable the Automatic Detection of Mail Connection Settings and Configure the Connection Manually

Mail can automatically adjust to certain mail services by changing connection settings. However, due to low compatibility with some mail services, Mail may be mistaken in the choice of parameters, as a result of which connection errors may occur.

If you have any problems, you should disable this feature and configure it manually:

  • Go to Mail -> Accounts;
How to Fix if Apple Mail not Sending?
  • Select your account and open the “Accounts” tab;
  • Go to the “Account Properties” tab and in the “Outgoing Mail Server (SMTP)” drop-down menu, select “Edit SMTP Server List”;
How to Fix if Apple Mail not Sending?
  • Select the SMTP server, go to the “Add-ons” tab and also uncheck the “Automatically detect and manage account settings” option.
How to Fix if Apple Mail not Sending?


After that, it is necessary to clarify the recommended connection settings. Usually they are listed in the “Support” section of your mail service website, but you can also find them by contacting technical support of the mail service directly. Sometimes there may be several configuration options, for example, using SSL encryption and without it. In any case, the problem with the SMTP is solved in a rather simple way.

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Hi there! My Name is Vincent Lago! My goal is to share insightful reviews, guides, and manuals for people looking to know more about current solutions for Apple hardware and OS. I have years of technological background knowledge including owning a custom iMacs & PCs which was using for different types of business. And now, I want to share my experience with you.

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