Eudora TM Search Contact Us
Support - Technical Support Resources and Knowledgebase User Forums - See users' online questions and answers about Eudora products, or post your own questions to the Eudora Community. Developers - Resources for Developers writing code to interact with Eudora Press - Press Releases and News Articles Testimonials - Read what others are saying about Eudora


550 or 553 Relay Denied Error (Windows)

Document ID: 1593HQ


When sending mail in Eudora, the error message "550 Relay Denied" is given by the SMTP server (Eudora may display "This message is not acceptable to your SMTP server. The message is not sendable until the recipient has been changed.") and mail cannot go out.


Most Internet Service Providers restrict access to their outgoing mail servers to prevent SPAM from being sent through their mail servers. If you are getting the "550 Relay Denied" error message, the outgoing mail server cannot verify who you are and will not allow you to send mail.

Mail Relay is when you connect to a mail server on another domain and try to send mail. For example, if you are connected to the internet through AT&T and then try to send mail using Earthlink's mail server. Historically, mail relay was fine - SMTP servers did not check to see who was sending the mail and would simply pass the mail on, no questions asked. But unsolicited bulk mailers (SPAMMERS) have taken advantage of this to send huge volumes of mail with fraudulent return addresses (so as not to be traced) - which slows down the server for the paying customers who have the right to use it and slows down servers everywhere with all that junk mail.

One of the ways to restrict access to an outgoing mail server is to verify that the computer is on the ISP's local network. When you dial your modem and connect to your ISP, your computer is given an IP address that identifies you as being a part of that ISP's network. If you have two ISP's and dial up to one and then connect to the other's mail server, it may prevent you from relaying mail because your computer is not identified as being on the local network for the provider whose mail server you are sending through.

For example, if you connect to the internet with AT&T and try to send mail using Earthlink's mail server, you will get a 550 error. To fix this, you should try to use the SMTP server for the provider you have used to dial up and connect to the Internet.

Another way to restrict access is to insist on a local domain return address. If you connect to the mail server for "" it may only allow you to send mail that is from "" -- if you try to send from another account and have the return address of "" it may restrict you from relaying to another server.

For example, if you connect to the internet using, it will check to make sure that your email says it's from . To fix this, change the "From" field under Tools: Options and make sure that your Return Address matches.

Note: Relay does not apply to sending to users local to the SMTP server. If you connect to "" and send mail to "" you are not relaying. Often this is confusing because it means that you can send a test message to yourself, but cannot send mail to other people on the Internet.

Eudora 6 introduces SMTP Relay Personality that allows you to use send mail from one Personality but send it in a way that is acceptable to the SMTP server. You can learn more about this feature at


[Search Again]

Did this document help you to resolve your issue?


| Home | Online Support | Open Source Development | User Forums | Contact Webmaster |

| QUALCOMM | Section 508 | Privacy Statement | Terms of Use |

© 1999-2009 QUALCOMM Incorporated. All rights reserved. QUALCOMM and Eudora are registered trademarks of QUALCOMM Incorporated. All other trademarks are the property of their respective owners.