Subscribe by email sending mail in spam folder


Subscribe by Email plugin in my users site are sending Emails to spam folder. How can I make them land in inbox?

The same problem happened to my blog and I solved that by my own. I even submitted a ticket here,

Now same problem happens to my site's in the network. It is really bad when the Email lands in spam folder and my sub-site users are not happy with it.

I hope this is caused due to from email address and the email is sent using my server. Refer that ticket I mentioned.

Please help me to solve this problem.