Update email ports from 25 to 587

With Mandrill I've run into the same issue as the OP in http://stackoverflow.com/questions/11356541/cant-get-mandrill-to-send-emails-from-rails-app so I suggest changing the default SMTP port from 25 to 587. 

Also I found this regarding sendgrid's SMTP ports: http://sendgrid.com/docs/User_Guide/smtp_ports.html
Merge pull request #278 from mazlix/patch-1

Update email ports from 25 to 587