Note: SMTP AUTH is not supported in Eudora 3.X or 4.X versions lower than 4.2.2. You will need to upgrade.
If you are using Eudora Pro 4.x be sure to upgrade to the latest version (4.2.2 at the moment of writing this text). You can download the updates from: www.eudora.com . You should be especially aware of 4.2.0 which claims to support SMTP AUTH in help files, but in fact it does not. Anyway 4.2.2 supports it and we recommend you use it. To enable SMTP AUTH you will have to edit the "eudora.ini" text file which is located in the eudora's directory. (Note: in here, do substitute jellico.net or tcnet.net or campbellcounty.com whatever is appropriate for your e-mail address) for domain.com
First quit your eudora, then open "eudora.ini" in your favourite text editor.
On the top of the file, you will see something like this:
[Settings]
SMTPServer=mail.jellico.com
SMTPPort=25
AsyncDatabase=0
AsyncWinsock=0
NC=1
Code=NC
POPAccount=user@domain.com
RealName=Your Name
ReturnAddress=user@domain.com
DomainQualifier=
PopServer=mail.jellico.com
etc...
To activate SMTP AUTH add 2 following lines, jest below the [Settings] line:
SMTPAuthRequired=1
SMTPAuthAllowed=1
Now start eudora and everything should work fine.