First of all, I want to learn how to do it, just for fun.
Okay, that was not what you initially said. Some comments below, nonetheless.
I will not recommend Google. Ever heard of data protection and data confidentiality?
Your data is stored confidentially by Google, obviously. Otherwise nobody would use their services.
And then you are completely dependent. Your are nothing for a huge company like Google. If they lose your complete e-mail database, they will tell you that they are awfully sorry. If at all.
The likelihood that Google loses your email is far less than the likelihood that your server has a disk failure, gets hacked and rm -rf'd, is stolen, burns in a fire, and so forth.
And no, running a mail server does not "consume a significant amount of resources". Any 10-year-old laptop can easily cater for a small business.
I meant human resources, obviously.
Besides, paying $6/user/month is actually very expensive for some small organisations. If you have 20 volunteers coming to the help in a small public library once a month, that would be $1440 a year just for e-mail services.
I'll say it again: Google is _free_ for nonprofits. Free: $0/user/month, for as many users as you want.
