Error: "Email Error: Your email was unable to send because the connection to mail server was interrupted"

This error appears when you sent someone an email message and your Internet service provider (ISP) or the ISP of the intended recipient rejected the message. To resolve this problem, run LiveUpdate and Full Scan using your Norton product.

This is not a problem with the Norton product. Norton includes Email Protection. Email Protection is an extra layer of protection that scans the incoming and the outgoing email. To do this job, Email Protection is placed between your email program and the ISP. If the ISP rejects an outgoing email immediately, your Norton product carries the message. But the message is really from the ISP.

The most common reasons for messages being rejected are:

The ISP (yours or theirs) thinks that the email is "spam." (Sometimes email is incorrectly detected as spam.)
The email address is incorrect or discontinued.
You sent an attachment that is larger than the ISP permits sent.

Make sure that the email address is correct. If it is, as a test, create and send a new message without any attachments. Finally, if you still need help, contact your ISP. You can also turn off Outgoing Email Antivirus Scan so that you no longer get these messages. Even though your outgoing email will no longer be scanned, Email Protection continues to protect your computer by scanning the incoming email.

Disable outgoing email scan

Open your Norton device security product.

If you see the My Norton window, next to Device Security, click Open.
Click Settings.
In the Settings window, click Antivirus.
On the Scans and Risks tab, next to Email Antivirus Scan, click Configure.
In the Email Antivirus Scan window, under What to scan, uncheck Scan outgoing email messages.
Click Apply.
In the Security Request window, from the drop-down menu, select Permanently, and then click OK.
In the Email Antivirus Scan window, click OK.
Click Close.