I want to send mails through my php application using swiftmailer. But I am confused. I do not want to let my mails go into the SPAM folders. So, Some one has told me to Configure the STMP correctly. I have searched a lot but could not find the solution. I want to know that is there any connection of STMP configuration with Mail sent to SPAM BOX. Should I use my Own Web Server STMP Setting while sending the mails with swiftmailer. Or should I use some other technique to prevent mails from going to SPAM Box. Actually, I am not going to send so many mails. I just need to send a confirmation mail, when a user get registered.
You will need to create a Sender Policy Framework (SPF) record for your domain where the emails are addressed from. This is to prevent spammers from forging emails that appear to come from your domain, since email recipients will look at this record to determine whether it originated from an authorized mail server. Unauthorized emails are usually treated as spam.
You can use Microsoft's Sender ID Framework SPF Record Wizard to create one (if someone knows of a better tool please say). Once your domain has been configured with the SPF record you can send a test email from your mail server(s) to check-auth@verifier.port25.com to test your configuration. Please be aware of common mistakes that are made when creating these records.
There's nothing you can do to guarantee anything but there are a few things you can do to help:
DKIM.SPF for your domain.SpamAssassin locally, and run a sample of your message through it, to see if (and how) it flags things. Adjust your message content to eliminate those flags.Google it, Here's a link on Serverfault with good info. https://serverfault.com/questions/48428/how-to-send-emails-and-avoid-them-being-classified-as-spam
And here's a check: http://www.brandonchecketts.com/emailtest.php
And http://blog.sendgrid.com/10-tips-to-keep-email-out-of-the-spam-folder/