Forum Moderators: coopster
How we can protect this, that mail client not mark mails as Junk/Spam.
That's the million dollar question! ;)
There are various things such as the format of the message (HTML v plain text), any "spammy" words such as "free" and various other things which I'm sure other people will be able to explain in more detail.
1. headers used for the actual emails
2. content of the emails, watch for poison/filter words
3. if your clients who aren't getting the emails are with a specific provider
4. your mail server set up
1. maybe show us what headers you are using on the messages
2. I use this list/product to check messages
[spamassassin.apache.org...]
3. is it AOL, hotmail, yahoo or just random ISPs?
4. this gets a lot more complicated and isn't always under your control.