The code you provided works as is for me using perl 5.8.4 and Net::SMTP 2.29 on a redhat enterprise 4 machine.

What operating system is this running on? Also what versions of perl and Net::SMTP?

Update - It's possible that you can't connect to that port, possibly because of a firewall or local permissions issue. For example, when running in a CGI script people using Fedora sometimes have a problem with SELINUX

Try this in the shell: 

 
telnet smtp.1and1.com 25

[download]
If you can connect you should see this: 
Trying 217.160.226.98...
Connected to smtp.1and1.com.
Escape character is '^]'.
220 smtp.perfora.net (mrelayus1) Welcome to Nemesis ESMTP server

[download]

In reply to Re: SMTP Authentication by imp
in thread SMTP Authentication by lv211

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