IMPORTANT
Usually, the port used for the Outgoing Mail
Server/SMTP Service is 25. However, there might be a situation where your ISP
might be blocking the use of port 25 for SMTP service. Many ISPs block port 25
in order to minimize the amount of spam sent using their network. If you are
facing issues sending mails using the default port 25, you can confirm with
your ISP whether port 25 is indeed blocked by them.
To circumvent this, Whois.com Pte Ltd
allows you to use an alternate port 2525 for sending mails if
port 25 is blocked -
a. Close the Eudora client.
b. Locate the directory in
your computer where Eudora is installed. The directory path would be
something like C:\Program Files\Qualcomm\Eudora.
c. This directory has a folder
named extrastuff, which has a file esoteric.epi.
d. Drag this file into the main Eudora
directory.
e. Start
Eudora and on the Tools menu, click Options.

f. Under the Ports option, enter
the alternate port number 2525 in the field
provided for SMTP Port.

g. Click OK to save the changes.