Questions[smtp](ubuntu)

I am trying to setup Ubuntu 20.04 with msmtp as a system configuration.

I installed msmtp (v1.8.6-1) and heirloom-mailx (v12.5-2+deb7u1build0.14.04.1).

Config file /etc/msmtprc (chmod: 600) has the following:

# Set default values for all accounts.
account default
auth           on
tls            on
tls_trust_file /etc/ssl/certs/ca-certificates.crt
logfile        /var/log/msmtp

# gmail
host           smtp.gmail.com
port           587
from           <account>@gmail.com
user           <account>
password       <password>

# Syslog logging with facility LOG_MAIL instead of the default LOG_USER
syslog LOG_MAIL

Log file /var/log/msmtp file mode is 660.

File /etc/mailrc (chmod: 600) contains the following:

set sendmail="/usr/bin/msmtp"

When I try to use sendmail to send an email from terminal I get the following sendmail: account default not found: no configuration file available.

The same error comes up if I directly invoke msmtp.

It broke my mail agent, since I need to redirect to an external smtp server, and nothing else seems to do that properly.

Main question:

Is it even possible to be be infected with a bot/spamming software on Ubuntu (or any other distro)?

Details:

My ISP blocked my port 25 (and 465) for outgoing connections (outbound connections, from home to remote server) to SMTP, so I can't use my business emails from home right now. Their reasoning for blocking me is: "because of you sending spam" which I'm not and they told me that if I'm not sending then my OS is probably infected...

I could use a comprehensive list of tools and guides to check the system (Ubuntu 13.10 14.04 64bit) for any infiltrates/malware/rootkits.

P.S.

• I also have Windows 8.1 (64bit) installed just because I also like to game on my home computer... but that's what I only do on Windows...when I have time...

• Wireless is off and even if it's on it's pass protected.

• Scanning of windows didn't reveal anything nor should have since
  there's windows and games installed there.

• I can connect to other ports for SMTP but our server uses 25 and that cannot change

• I also tested connecting to port 25 from windoze (using thunderbird)

• I use thunderbird for email client on ubuntu and tested a few others just to verify that it was not a misconfig of thunderbird.

• Telneting also outputs connection timeout...

EDIT: My ISP still refuses to unblock me... Maybe I'll have to open up 587 on the server, since that isn't blocked at the moment (I can still use Gmail)

EDIT 2:

I guess today I was connected with another tech from my ISP's support and told me that there isn't a block from them... I was furious!!! I don't know what was the previous tech doing... maybe he is new and was reading from a script..

So I tested another ISP via tethering from my phone and I successfully managed to send emails through port 25. Essentially I didn't change anything, only the ISP. Are they kidding me? Maybe the tech-support doesn't know how to interpret what they looking on their screens for my account or could it be something else?

Another step I took was to fully reset my router to it's default settings and get another dynamic IP. Still no connection to port 25.

I'm planning to get a used router from some friend or something to test with another router just to be sure the problem lies with my ISP.

EDIT 3: It's been awhile since my last update to this question. I moved back to my old house (which is in a different part of the country) where I have the same internet provider. The same company!! My settings just work as expected. I can send emails just fine using port 25. I bet the problem was with that nasty ZTE router that the ISP hands out to new customers.

Right now my Helo Address = localhost (helo=localhost). Is it better to set this to my server's domain name? If so, how do I change it? I'm running Ubuntu 12.04 and Postfix. Thanks.

I need to set up an SMTP server, really the goal is so that this server has no communication with the outside world, I would create the server, and would want a mail client looking at messages the server generates (brownie points if all messages go into the same inbox). This is basically to test out my mail system and see how it looks on different clients, while at the same time not actually sending emails to people.

Any advice, any known systems that do this?