使用sendmail发送邮件到gmail

Question

I have a server on OVH and I'm trying to send some mail to my Gmail address using sendmail. I installed sendmail with apt-get on debian, and echo "Subject: test" | /usr/sbin/sendmail -v mymail@gmail.com echo "Subject: test" | /usr/sbin/sendmail -v mymail@gmail.com works. However Gmail puts the mail in the spam folder and says the mail is not authenticated. I have no knowledge of how email works and from what I've seen I could use SPF or DKIM to provide authentication, but it seems it requires admin access to ovh DNS servers. What would be the easiest way, using only admin access to the server that sends mails, to make sure emails sent from it are not marked as spam ?

Thanks

Answer 1

There are no easy way. That's the simple answer.

Google Mail is fighting spam every second, every day, all year. To get mail delivered directly to the inbox requires time and patience and there are no shortcuts. If there where, spammers would have it way to easy!

You are very correct that Google's SMTP servers will ask you to beef up your SMTP mail headers to include better authentication and security. There's no way around it if you want to be on good terms with Google's SMTP servers.

Here is a list of things to consider

• SPF (Must have, also to defend spam sent in your name)
• DKIM (Must have, this is somewhat a step up from SPF)
• ESMTP (Google likes it when you talk to them encrypted)
• Bulk headers (Use them if it's bulk, no reason to lie!)
• Unsubscribe headers (Use them if you are sending out maillist content)
• SMTP relay's with nice Senderscores (Easy access to the inbox, but cost)
• SMTP relay's with good reputation (Easy access to the inbox, but cost)
• Feedback loop headers/setup (If you send large amount of mails)
• Only use "warmed up" SMTP relay servers (Mostly used by bulk senders)
• Reverse DNS to match HELO/HELO (Mismatch can make problems)
• Static IP (It's a given)

As you can see it's no simple task to "just" send an email to Google and expect it to be passed along to the users Inbox without getting targeted as spam.

Most of the options above requires extensive server knowlagde or that your hosting provider supports it. You need to have access to change your own DNS records but also the SMTP server that you send your mail from needs to be setup with the things in advance.

Now to the:

"How to send emails to Google Mail that always land in the inbox for dummies"

Well you basically buy your way into the inbox. Use SMTP services like Mailchimp, Amazon AWS-SMS (Simple Mail Service) many if not all of these services have already setup DKIM, SPF and are on good terms with Google. They do however have many rules and what and what not to do so if you don't follow the rules they will close your account right away.