Unable to send an email to following address in Yahoo! mail

yahoo-mail

I've had a complaint from a customer that they can't reply to our user generated email addresses – there are various reasons for the format below, but the long and short of it is that the Yahoo! Mail web interface doesn't like it and just spits out an error:

We cannot find a match for this email address:

143b56c5-a2ad-40ac-a6c8-ad953d681baed023140d-9280-459a-bca9-ad47e54e61bd@example.exampledomain.com

Please use an email address that looks like user@example.com or a
nickname or a distribution list name from your Yahoo! contacts.

Does anyone know why this isn't passing the Yahoo! Mail filter?

Best Answer

It appears the local part / username of the email address must be 64 characters or less for it to be accepted by Yahoo! Mail.

This restriction is not seemingly enforced by all providers, but it is in the spec here:

http://en.wikipedia.org/wiki/Email_address#Syntax

The format of email addresses is local-part@domain where the local-part may be up to 64 characters long and the domain name may have a maximum of 253 characters - but the maximum 256 characters length of a forward or reverse path restricts the entire email address to be no more than 254 characters

Related Solutions

Hacking, Spoofing or Malware explosion

You have listed the three reasons, so it's good that you are aware of them... Let's go through them:

Hacking

You handled this just fine by quickly changing your password.
Spoofing

The SMTP protocol (the connection used to send mails) allows anyone to specify the address the mail originates from. So for instance, I could send a mail from any Yahoo address without knowing any password, it's possible but it's illegal...

Most of the times, you can't do much against spam but if it's keep happening you can at least try to identify where the mails are coming from. You can do this by requesting someone who received your mail to check the mail headers and send you the data that is in there.

This allows you to inspect the IP/host it comes from and inform their ISP about the spam.
Malware explosion

You handled this just fine by verifying the computer is clean.

Yahoo Mail – Unable to Send to This Email Address in Yahoo Mail

You have a period at the end of the email address

users-digest-subscribe@httpd.apache.org.
                                       ^

It should be users-digest-subscribe@httpd.apache.org (no period)

Period makes the email address highlighted in red

Removing the period gets me a reply from the Apache Digest with the subject

confirm subscribe to users@httpd.apache.org

Best Answer

Related Solutions

Hacking, Spoofing or Malware explosion

Yahoo Mail – Unable to Send to This Email Address in Yahoo Mail

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