When used SMTP settings mail received in SPAM Folder

Product Support
1

When I used SMTP authentication for sending mail from Mautic, it end up into SPAM folder. While investigated mails received are not having Message Headers. Can anybody help how I can solve this issue.

2

When I used SMTP authentication for sending mail from Mautic, it end up into SPAM folder. While investigated mails received are not having Message Headers. Can anybody help how I can solve this issue.

3

There are a few factors
SMTP server maybe is Blacklisted
DKIM Configuration
Bat use of words that trigger spam filters.