Move Mailer to SwiftMailer about silverstripe-framework

[chillu]

Related discussion: https://groups.google.com/forum/#!searchin/silverstripe-dev/phpmailer/silverstripe-dev/YRxMGHgQ0AU/M5lOJswBUzIJ

[tractorcow]

I'd made a bit of a rewrite of this for 3.2, so check the master branch.

[edlinklater]

@tractorcow Yep, am working against master, thanks.

[tractorcow]

It would be good to do #3057 at the same time

[dhensby]

I'm kind of working on this https://github.com/dhensby/silverstripe-framework/tree/pulls/4/mailer

[tractorcow]

I'm also in favour of swiftmailer... good job @dhensby !

[patricknelson]

Would like to see this in 4.0. I've wrestled a bit with the mailer a few times myself and this would be helpful @dhensby. Is anyone aware of any major advantages of SwiftMailer over Zend_Mail or vice versa? e.g. security, activity, general features and etc. I know we already use Zend components elsewhere in SS.

[tractorcow]

Related issue: #5719

[sminnee]

Pull request available in #6466

[sminnee]

Merged!