I am searching free mail software which includes unsubscribe option as well.
If you use email marketing software on your own PC, probably you need to do the unsubscription through other options, because there must be a 24*7 server to handle the customer request when they click on the unsubscription link.
For example, I use 1and1Mail (www.1and1soft.com) to send mass emails, and inside each email, I embed a link to my website written in PHP and it will automatically record if the link is clicked or not. And my website will send an email to me to notify me that the user has unsubscribed.
Hope the above helps.
I would suggest looking at MailChimp.com
There's a few other scripts out there that I found, but can't remember the names. Let me know if you want to know them and I can find them for you.
If you're looking for a free email marketing webapp that users on your list can unsubscribe from, I've heard good things about MailChimp, but yea please provide more info.
I also recommend Aweber. Probably the most comprehensive email marketing
tool out there.
I'm afraid I don't quite understand what you need the unsubscribe option for. Are you looking for a temporary eMail account that you can trash when it receives too much spam? Or are you looking for ways to block specific mails, for example spam?
For temporary eMail accounts, please have a look at the following article from Will:
Five Free Temporary Email Services To Avoid Spam
If that's not what you're looking for then please provide us with more details. Thank you!