Charter Postmaster Services

Charter has developed various policies and procedures to protect our customers from abuse.

This site has been developed to give bulk e–mail senders, ISPs, e–mail service providers, postmasters, and domain administrators a location from which to learn about these policies and the necessary steps required to resolve problems.

If you were directed to this site because of a specific error received when trying to send an e–mail please find the error listed below for additional information and troubleshooting tips to resolve the issue

General Information

Determining Spam

Charter uses several different tactics to determine if a message is SPAM. The primary tactic is our enterprise anti-spam application. A message will not be accepted by our mail servers if it is flagged as SPAM.

Handling Spam

Charter does not accept email that is flagged as spam by our anti-abuse detection system. Email flagged as spam is dropped "on the wire". Anyone attempting to deliver mail to Charter's mail servers that our anti-spam application has flagged as spam should receive an SMTP reply code of "550 Message Rejected".

back to top »

Mail Server Settings

Residential customers are limited to a maximum single message size of 10 Megabytes.

Mail Client Server Settings (Outlook, Outlook Express, etc):

Mobile

Desktop

These settings should be applied to your Desktop Computers. Your mobile devices (including laptops) should use the Mobile settings above

• Username: username@charter.net  Note: Make sure you enter @charter.net after your username or you will be unable to login
• Password: The password you use to login to your Email account
• Server Type: IMAP
• Incoming Mail server: IMAP.charter.net
• Port: 143
• Outgoing Mail Server: SMTP.charter.net
• Port: 25
• Web Mail Address: http://www.charter.net/

back to top »

Rate Limiting

Rate limiting is an anti-abuse network protection method. Charter customers are limited to sending a set number of messages per hour. Additionally, there are a set number of recipients per message allowed. This policy is standard industry practice. The rate limit threshold is a dynamic number configurable by system administrators which has been set in accordance with standard industry practice. Rate limiting ensures mail system stability and usability for all Charter customers

Real-time Blacklist (RBL)

RBL Stands for "Real-time Blacklist". Charter uses multiple RBLs. One RBL is intended to keep track of Charter Customers that are known to have been spammers. These customers have violated the Terms of Service. Another RBL is leveraged to stop inbound mail from spammers at the network layer whose IP blocks are known to be owned by spammers. An IP that is on an RBL will not be able to send email to the Charter mail complex

Virus Infected Email

Since most virus infected email is spam, our anti-spam system will drop and not process delivery of those emails.

Virus infected emails that are not flagged as spam will be delivered to their intended recipients.

Charter subscribers concerned about being vulnerable to virus infected emails should protect their computer with the Charter Security Suite™, which offers the latest in virus prevention and protection technology. The Charter Security Suite™ is available to all Charter Internet subscribers at no additional charge. Click here for more information and to download the Charter Security Suite™.

back to top »

SMTP Error Codes

Information below the error message offer suggestions for self-diagnosis.

CHTR 301 Error Code – Security Alert

This is an alert that abnormal activity has been detected on your e–mail account. To protect your privacy, access to your e–mail account via Charter webmail has been temporarily blocked. You can continue to use your Charter e–mail account via Outlook Express or other e–mail client.

Your security and privacy is important to us. Your e–mail address has been temporarily locked due to recent suspicious activity.
To ensure that only authorized users are accessing webmail with your e–mail address:

1. Log in to My Account at http://www.charter.com.
2. Click the Internet Services & Tools tab.

3. Remove any email addresses that you did not create.

NOTE: This can also be performed by accessing Charter Email with the Head of Household account.

4. Change the password for the remaining email addresses (Strong Password Tips).

NOTE: This can also be performed by accessing Charter Email with the Head of Household account

5. Click the My Profile tab.

6. Change the My Account password using a strong password. (Strong Password Tips)

Your account is temporarily locked due to too many login failures. Please try again later or contact your administrator.

If you are unable to remember your e-mail password, you can:

1. Reset it by logging into My Account using the same steps outlined above. OR
2. Chat online with a trusted advisor. OR
3. Speak to a trusted advisor by calling 1-888-438-2427.

back to top »

Webmail Error Codes

Information below the error message offer suggestions for self-diagnosis.

421 Charter.net connections refused from (IP Address) E1550

Possible Issue: Client has too many connections open.

Troubleshooting: This could indicate a business is running their e-mail through the residentail service. OR
A Charter Internet subscriber's computer could be infected with a virus and botnet activity has been detected.

421 Service Not Available - Client IP sending email is on Charter RBL

Possible Issue: The client IP address has been listed on Charter's "Real-Time Blacklist".

Troubleshooting: IP address has been identified as sending SPAM. If the IP address is not sending SPAM, follow steps outlined in error "550 [MESSAGE ID] Message identified as SPAM".

421 Charter.net Lost (Connection timed out)

Possible Issue: Sender network connectivity issue.

Troubleshooting: Perform standard network troubleshooting steps.

452 [FROM EMAIL ADDRESS] send quota exceeded: try again later E2210

Possible Issue: The sender has exceeded the maximum number of message allowed per hour.

Troubleshooting: Refer to the FAQ section; "What is rate limiting?"

452 [FROM EMAIL ADDRESS] come back later E1520

Possible Issue: The sender's mail client has exceeded the number of messages per session.

Troubleshooting: Wait at least one hour from time of last send before resuming the process of sending e-mail from the mail client.

503 Sender Already specified - Too many invalid email addresses

Possible Issue: There is a limit on the number of invalid e-mail addresses the sender can attempt to send e-mail messages to.

Troubleshooting: Only send e-mail messages to valid e-mail accounts.

550 [MESSAGE ID] Message identified as SPAM - Please visit http://www.charter.com/postmaster E5110

Possible Issue: The content of the e-mail message, or a portion of it, was flagged as SPAM by Charter's anti-spam detection system

Troubleshooting: If the e-mail message was incorrectly identified as SPAM, you may submit it to Charter for review. To do this, send the ORIGINAL e-mail message to unblock@charter.net.

IMPORTANT: The message must not be forwarded. You must resend the original message. Allow ample time for processing. Charter is unable to respond to the submitted messages.

552 Message size exceeds allowed maximum message size

Possible Issue: The sender is attempting to send an e-mail with an attachment that exceeds the allowed maximum message size.

Troubleshooting: 10 Megabytes is the maximum allowable single message size for residential customers.

553 [FROM_DOMAIN] does not exist E2110

Possible Issue: The sender is attempting to send e-mail messages from a domain that does not exist.

Troubleshooting: Verify the sender's domain is a valid domain.

553 [TO DOMAIN] does not exist E2120

Possible Issue: The domain the sender is attempting to send e-mail messages to does not exist.

Troubleshooting: Verify the recipient's domain is a valid domain.

571 You must connect from Charter IP space. E1110

Possible Issue: The sender is unable to relay messages through Charter's mail complex.

Troubleshooting: Relaying is prohibited by Charter.

If you are using a laptop computer make sure you are using Charters Mobile Email settings with your Email client

If you are receiving this error message while on Charter's IP space, please chat online or call us at 1-888-438-2427.

back to top »