Global SMTP - Send Your Email From Anywhere

The root cause of your problems is your home Internet Service Provider (ISP) is trying to reduce spam, so at least they do this with the right intentions!
Your internet company provides you with a free to use email sending server, this is your SMTP (Simple Mail Transfer Protocol) server, which allows you to send emails when you are directly connected to them. When you go away from home you are no longer directly connected to them, in fact you are using a completely different internet provider. As your provider no longer knows who you are, as far as they know you could be anybody now, they don't allow you to use their servers for sending emails.
Some internet providers have combated this problem by allowing a secure login function for collecting and sending you emails, you can try asking your provider if they offer this service.
However if you use a 3rd party email, for instance you have your own company domain name and you want to use that email address it is unlikely your ISP will be too willing to help you!

You have a number of options; you may find that there is a web interface to your email which you can use. This would allow you to login to your email from any internet connection as long as you had access to a browser (Internet Explorer, Firefox, Safari etc). There are normally severe limitations to this service though, sometimes you will not be able to access your old emails, or any emails you send through this service will not appear in your sent folder on your computer. However it is free!

Another free service if your own don't normally have a web interface to your email is to use a thrd party service, such as Mail2Web. These allow you to interface with just about any email account there is just a long as you know the address and password. However you should consider the fact you are handing over your password details to a 3rd party site, something you may not want to do.

If you are like me then you will not want to give out your passwords unless you really have to, and in this case you don't. You can get 3rd party SMTP email services for very little money these days, we are talking less than $2 a month!

With such a service you still collect your email using the same program you always use, the only difference if you change your email settings to send emails via the 3rd party server. They allow you to connect from anywhere because they use a login system to prove who you are. Don't worry you don't have to type in a password and username each time (well not unless you want to) as it's stored by your email program.

As an added bonus because you are not revealing your own mail passwords to anybody else there is no chance using such a service can compromise you existing emails.