Sending limits and blocked file extensions of your Comcast Email

Find out more about your email sending limitations and settings.

Providing a secure internet experience for all our customers

Comcast works hard to make sure your email experience is as easy and safe as possible. By placing limitations on the amount and size of email an account can send, we can help prevent spam accounts from filling your inbox.

Comcast has put the following sending limits in place for our residential Xfinity Internet customers:

An email message can be sent to a maximum of 100 recipients. Any messages sent to over 100 recipients will not be delivered.
Xfinity customers can email up to 1,000 recipients per day. If an account exceeds the 1,000-recipient limit, the account will not be able to send for the remainder of the day.
The maximum size of an email cannot exceed 25 MB; this includes attachments, headers, text, formatting, etc.

Often, users are unaware their computers are being used to send spam. These limits allow us to cut down on the harm infected computers can cause on our network.

Blocked file extensions

Comcast blocks certain file extensions that are often associated with spam or harmful software. The following email attachment types are not allowed:

.vbs
.pif
.scr
.bat
.com
.cmd
.msi
.reg
.exe

Upgrade for higher daily email limits

If you send out a large number of legitimate, requested email messages per day, we encourage you to reduce your daily volume to 1,000 email recipients.

We also suggest upgrading to a business email account through Comcast Business Services, which provides higher daily email limits that may meet your needs.