How to Set Up Email on Plesk So It Does Not Land in Spam

Plesk includes a full mail server (Postfix and Dovecot), and creating a mailbox takes a minute. Getting mail from it delivered to Gmail and Outlook inboxes takes a little more, because receivers judge every message by the records around it. Do the following once per domain and it will work for years.

1. Give the server a proper hostname

The mail server introduces itself by hostname; it must resolve, and it must match the reverse DNS. In Plesk, Tools & Settings → Server Settings → Full hostname: something like mail.example.com or s1.yourhost.com. Add an A record for it pointing at the server IP.

2. Set the PTR (reverse DNS)

The PTR maps the IP back to that hostname, and it is set by whoever owns the IP — your hosting provider, in their panel or by ticket. Verify:

bash

dig -x 203.0.113.10 +short
# mail.example.com.

If this returns nothing or a generic name like 203-0-113-10.provider.net, Gmail will junk or reject your mail regardless of anything else. Details: reverse DNS and why email needs it.

3. Create the mail domain and mailbox

Mail → Create Email Address on the domain. Set the address and a strong password. Under Mail Settings for the domain, confirm Activate mail service is on and the mail server IP is the one with the PTR.

4. SPF, DKIM, DMARC

Under Mail → Mail Settings → the domain:

Tick Use DKIM spam protection system to sign outgoing email messages. Plesk generates the key and adds the default._domainkey record if it hosts your DNS.

Then check the domain's DNS zone (DNS Settings) has:

example.com.         TXT  "v=spf1 a mx -all"
_dmarc.example.com.  TXT  "v=DMARC1; p=quarantine; rua=mailto:dmarc@example.com"

Plesk creates the SPF record automatically; add the DMARC one. If your DNS is at another provider, copy all three records there. What each means is in SPF, DKIM and DMARC explained.

5. Turn on TLS

Tools & Settings → SSL/TLS Certificates → Certificate for securing mail: assign the server's Let's Encrypt certificate. Outgoing mail is then encrypted in transit, which receivers score positively, and your mail clients stop warning about the certificate.

6. Set sending limits

Tools & Settings → Mail Server Settings → Outgoing mail control: limit messages per hour per mailbox (e.g. 100) and per domain. This is not for you; it is so that if one mailbox password leaks, the spammer sends 100 messages instead of 100,000 and your IP's reputation survives.

7. Test

Send a message from the new mailbox to a Gmail address and open Show original. You want:

SPF:   PASS
DKIM:  PASS
DMARC: PASS

Then send one to the address mail-tester.com gives you and read the report; 9/10 or above is right. A lower score lists exactly what is missing.

Check the IP is not on a blocklist — a previous tenant of the address may have earned one:

bash

# quick check against Spamhaus for 203.0.113.10 (octets reversed)
dig 10.113.0.203.zen.spamhaus.org +short
# empty = not listed

Or use mxtoolbox.com's blacklist check. If listed, the provider's ticket queue is the way to get a clean IP.

8. Mail clients

Give users these settings, which Plesk shows when you click a mailbox:

	Value
Incoming (IMAP)	`mail.example.com`, port 993, SSL/TLS
Outgoing (SMTP)	`mail.example.com`, port 465, SSL/TLS (or 587 STARTTLS)
Username	the full address

Device-by-device instructions: setting up Plesk email on iPhone, Outlook and Gmail.

Why mail still goes to spam sometimes

Authentication passing is necessary, not sufficient. Content, sending patterns and the reputation of the IP and domain all count; a new domain sending 500 messages on day one looks like a spammer even with perfect records. The full list of causes is in why your emails go to spam.

On VPSPioneer shared and reseller plans, steps 1, 2, 5 and 6 are done at the server level and 3–4 happen automatically when you add a domain; you create the mailbox and it delivers.