问题
I am able to send an email successfully to my gmail account and the mail goes to the INBOX, but when i send it to hotmail it reaches the Junk/Spam folder?
I am using System.Net.Mail to send email.
回答1:
Gmail and Hotmail will be running different junk mail filters so while your e-mail is acceptable to one it might not be to the other.
Make sure that your e-mail is well formed:
- the headers are valid
- the content type matches the body
- the title is set and relevant to the content
- the body doesn't contain a lot of images/links etc
You could try sending the mail as plain text rather than HTML.
The fall back position is to tell your subscribers to add your sending e-mail address to their white list. It's not ideal, but it will allow your e-mails through.
回答2:
A lot of junk email filters will check if your email originated from ip address(es) that your mail server(s) has using a MX record lookup.
You can add your application server to your DNS using SPF records.
http://en.wikipedia.org/wiki/Sender_Policy_Framework
回答3:
Each ISP maintains their own filtering list. This is often based on sender reputation. To get out of the junk email folder, you need to improve your sender's reputation.
Hotmail/MSN have an information page here: http://mail.live.com/mail/services.aspx
If you run your own server, perhaps you get get enrolled into the sender information services. This will provide some insights into why your email is being treated as junk.
Also, be sure you have SenderID (SPF) records setup for your domain and that they are accurate.
http://www.microsoft.com/mscorp/safety/content/technologies/senderid/wizard/
I am not sure if Microsoft is checking DKIM/DK records yet but it is also useful to specify those as well.
Be sure your remote DNS is configuration properly.
Lastly, you may want to monitor your sender's reputation using: https://www.senderscore.org/ http://www.senderbase.org/
Also, look out for any forwarding of email from your server to Hotmail related addresses. If you have a user forwarding email and then marketing it as spam, your server's IP will get dinged for it.
回答4:
As an addon to the existing answers. Had a case of this today, and resolved it. Only Hotmail was flagging it.
Everything was perfect, SPF records, etc. So I had to do some black box testing to find out what was causing it to go into spam.
Long story short, finally when changing the name in Outlook to "S" instead of "Stéphanie", followed by her last name, it went to the recipient's Hotmail's inbox right away.
But putting back Stéphanie or Stephanie in her name always caused the email to go in Junk. And as soon as I removed it, it started going to Inbox again.
It was an interesting case, as it seems Hotmail's algorithm increases the spam score when it sees "Stéphanie". Who knows, perhaps due to all the adult nature spam emails sent under that name. But moral of the story, test the name as well when troubleshooting.
My story is documented story there. Hope it helps someone.
来源：https://stackoverflow.com/questions/3854590/mail-goes-to-junk-folder-in-hotmail