Emails sent through SMTP on VPS are considered to be spam

Question

During our business we have to make regular mailing to our clients: invoices, information emails, etc.

Previously we received and sent emails using mail server of our hosting provider. But as the number of clients increased, we have to order VPS and install our own SMTP server their for performing our mailings.

So, now we have default provider mail server for receiving emails, let it be business.com. We have email accounts like [email protected], etc. We use this mail server to receive emails and manage our email accounts.

And we have SMTP server which is running on VPS. We use this SMTP only for sending emails with From addresses like [email protected]. VPS has default DNS records created by provider, let it be IP.AD.RE.SS <-> ip-ad-re-ss.provider.com.

Mailings are made using either desktop email clients or custom Java-based application which uses JavaMail for sending emails.

The problem is that most of emails sent by us are placed in spam folders in clients email accounts. Clients have their email in Gmail, Yahoo, Hotmail, etc.

Could you please tell what is the most probable reason and solution of described problem?

Are there any service in Intranet where we can send test email and get an answer with description why this email could be considered to be spam?

Solution 1

You need to make sure that your email server is setup properly so that these mails are not marked as spam. As mentioned, one of the most common reasons is Reverse DNS. Most of the big providers require that you have a correct RDNS pointer record setup for your mail server before they will receive mail for you.

You also want to check that the IP your provider has given you has not been blacklisted, use a facility like this one to check. If it is on the list, if it's a new IP you have been given you can probably get your provider to give you a new one, if you've had it a while then it will be harder to prove that you are not the ones who got it blacklisted.

Solution 2

Try this Email Server test. It does a whole load of checks to see why your emails could be labeled as SPAM

Solution 3

Most likely a reverse DNS issue. The only way to know for sure is to see the header information of the emails in the junk/spam boxes of your clients. Your VPS provider should be able to setup a reverse DNS record for your domain.

Comments

[ilya]

Do you mean record for our VPS IP? Reverse DNS has record. IP.AD.RE.SS is resolved to ip-ad-re-ss.provider.com successfully.

[ilya]

By the way, do mail providers fill headers of emails which are marked as spam with information why these emails were considered spam?

[xeon]

Yes. The provider will fill headers with information that can be used to determine the root cause. You should see something like X-Spam-Status and that will give you the reasons why it was marked as spam and the score.

[ilya]

Thanks. We followed its recommendations and hope that they will help us and there won`t be problems during our next mailing.