Setting Up a SMTP Server with Postfix
A few months ago, my university (University of Waterloo) blocked the ability for students to send e-mail from their university-issued accounts from within Gmail. Essentially, what they did was block Gmail from connecting to the university's SMTP servers to send e-mail through them (not to them - there's a difference). Students could still send e-mail from within Gmail with their university-issued accounts as long as they opted to use Gmail's own SMTP servers, but this would usually append their personal Gmail addresses to all e-mails sent out and make them appear as being "On Behalf Of x@gmail.com".
For privacy and other reasons, university staff usually ignore all e-mails sent form personal e-mail accounts or those appearing "On Behalf Of" someone's personal e-mail address. Because I use Gmail as my e-mail "hub" or client, since I can access it pretty much anywhere, I needed to find a workaround. After some thorough research, I chose to setup my own SMTP server on a VPS I have using Postfix in combination with SASL and SSL/TLS.