Hmm, after a bit of searching I found
stunnel, which can provide the SSL I was looking for.
To be able to use it, you'll need the stunnel.exe (very small), and the OpenSSL libraries (libssl32.dll and libeay32.dll), all in all a 2 MB package

, but apparently the only way to do this...
You'll need to install the stunnel.exe (as a service) first, you can do this by invoking it with the -install suffix (command line). Now it's installed, but not running (yet)
Gmail example:
create a stunnel.conf file, and fill in the following info:
Code:
# GLOBAL OPTIONS
client = yes
output = stunnel-log.txt
debug = 0
taskbar = no
# SERVICE-LEVEL OPTIONS
[SMTP Gmail]
accept = 127.0.0.1:1099
connect = smtp.gmail.com:465
[POP3 Gmail]
accept = 127.0.0.1:1109
connect = pop.gmail.com:995
Run the following:
Code:
Run, net start stunnel
This will start the stunnel service. Now that it is running, we can use it:
Now the following should work with getmail (receiving e-mails):
Code:
run, getmail -u yourusername -pw yourpassword -s 127.0.0.1 -port 1109
And the following with blat (sending e-mails):
Code:
Run, Blat -install smtp.gmail.com yourusername@gmail.com
Run, Blat - -body "this is a test e-mail" -subject "a test" -to someone@somewhere.com -u yourusername -pw yourpassword -f yourusername -debug -server 127.0.0.1:1099

You need to change your settings in Gmail for this to work:
"Forwarding and POPAccount" section:
1. Enable POP for all mail (even mail that's already been downloaded)
2. When messages are accessed with POP: keep Gmail's copy in the Inbox.
After you downloaded your e-mails with this setup, Gmails settings will have changed (the downloaded e-mails will be flagged for no redownloading). In order to get the same messages again, you'll need to reenter the mentioned settings...
You can adapt stunnels config file to use different setups... stop it first by using net stop stunnel, change the config file and start the service again with net start stunnel...
Useable: gmail.com (1GB POP/SMTP), spymac.com (1GB POP/IMAP/SMTP), bgxmail.net (10GB POP/IMAP), icmail.net (1GB POP/IMAP/SMTP)
Not-useable: hotmail.com/msn.com, yahoo.com (you need to pay for POP/IMAP/SMTP at these free e-mail providers now)