I received a private message today from a forum user who is mac based asking for help in resolving Eudora's "550 5.7.1 Authentication Required Error"--while there a number of threads about this issue, the solution(s) offered are primarily geared towards pc-based (Windows) systems.
I've just received a reply from the user telling me that the info I provided resolved the issue so I figured I'd post the info in the open forum in hopes other Eudora mac users would find it helpful.
Eudora's "550 5.7.1 Authentication Required Error" has to do with the setting for CRAM-MD5 which on the pc-side is resolved by adding the following line in the "[Settings]" section of the Eudora.ini file:
If you scroll down the page of the above url, you'll see the following instructions one of which disables CRAM-MD5--I've been told that command does indeed fix the authentication error problem:
The real solution to this problem is for the server to be fixed such that it correctly supports all authentication mechanisms it advertises. Since you probably have no control over the server, the following URLs will cause Eudora to "ignore" specific authentication mechanisms that the server advertises. Copy and paste one of the URLs below into a new message in Eudora and double click on the resulting URL.
To disable cram-md5: <x-eudora-setting:12909=cram-md5>
To disable login:<x-eudora-setting:12909=login>
To disable plain: <x-eudora-setting:12909=plain>
You can mix and match mechanisms to disable. For example, to disable cram-md5 AND login:
The following is the master mac menu for Eudora HELP and it can be a bit flakey but there is some useful info there: