Email Settings: IMAP, SMTP, POP3 Ports and Server Details

To set up a domain email account ([email protected]) in Outlook, Thunderbird, iPhone or Android, you need three things: the incoming server (IMAP or POP3), the outgoing server (SMTP) and the correct port/encryption settings. This guide explains all of them with concrete values.

IMAP or POP3?

	IMAP	POP3
Where email is stored	On the server; devices stay in sync	Downloaded, deleted from the server (by default)
Multiple devices	Ideal — phone + computer see the same mailbox	Problematic — each device a separate copy
Server space	Uses it (counts toward your quota)	Does not (frees up once downloaded)
Recommendation	This, for most users	Only for single-device users who want a local archive

Standard port and encryption values

Protocol	Port	Encryption	Note
IMAP	993	SSL/TLS	Preferred
IMAP	143	STARTTLS	Alternative
POP3	995	SSL/TLS	Preferred
POP3	110	STARTTLS	Alternative
SMTP (outgoing)	465	SSL/TLS	Preferred
SMTP (outgoing)	587	STARTTLS	Alternative — "SMTP authentication" must be on

Do not use port 25 in the client settings. Port 25 is for server-to-server transfer and almost all home/mobile ISPs block it.

What should the server name be?

At most hosting providers the incoming and outgoing server name is:

mail.yoursite.com

Alternatively, the provider's own server name is given (e.g. srvXX.provider.com). The "Email accounts" → "Connection settings" / "Configure Mail Client" section in your panel shows the exact values.

Username: usually the full email address ([email protected]), not just name.
Password: the email account's password (not your panel/hosting password).

Setup by application

Outlook (new and classic)

File → Add Account → type the email address → Advanced options → "Let me set up my account manually".
Choose IMAP.
Incoming: mail.yoursite.com, port 993, SSL/TLS.
Outgoing: mail.yoursite.com, port 465, SSL/TLS.
Password → Connect.

If new Outlook insists on autodiscovery and it fails, you may need to set the account up on the web first and sync it, or switch to classic Outlook.

Thunderbird

Settings → Account Actions → Add Mail Account.
Name, email, password → "Configure manually".
Enter the values from the table above → "Re-test" → Done.

iPhone / iPad

Settings → Apps → Mail → Mail Accounts → Add Account → Other.
"Add Mail Account" → enter the details.
IMAP tab: incoming server mail.yoursite.com, username the full email, password. Outgoing server the same details.
Save. iOS tests the connection; for the "SSL not available" question say Yes/use SSL.

Android (Gmail app)

Gmail → profile top right → Add another account → Other.
Email + Personal (IMAP).
Password → Incoming server settings: mail.yoursite.com, port 993, SSL/TLS.
Outgoing server: mail.yoursite.com, port 465, "Require sign-in" checked.

Common errors

"Outgoing server rejected the password": SMTP authentication is off. In the client, turn on "Outgoing server (SMTP) requires authentication" and choose "use same settings as incoming server".
I can receive but not send: the ISP may be blocking port 465/587, or try the alternative port. Switch to mobile data and test.
Certificate warning: use the provider's main server name (srvXX...) instead of mail.yoursite.com — the certificate may be issued to that.
Authentication keeps failing: make sure you entered the full email address as the username. Reset the password from the panel.
Old emails not showing (POP3): another device may have downloaded them due to the POP3 "delete from server" setting. Switch to IMAP.
My sent emails land in spam: this is not a client setting — your domain is missing SPF, DKIM and DMARC records.

At Arcnar: When you create an email account, the panel shows the setup values for your device and ready-made SPF/DKIM records. You can access webmail from the panel with one click.

Frequently asked questions

Should I use IMAP or POP3?

IMAP for almost every user. Emails stay on the server and your phone, computer and webmail see the same mailbox in sync. POP3 downloads emails and deletes them from the server; it only makes sense for single-device users who want a local archive.

Which ports should I use for IMAP and SMTP?

IMAP: 993 (SSL/TLS). Outgoing SMTP: 465 (SSL/TLS) or 587 (STARTTLS). POP3: 995 (SSL/TLS). Never use port 25 in the client settings — most ISPs block it.

I can receive email but can't send, why?

SMTP authentication is usually off. In the client, enable "Outgoing server (SMTP) requires authentication" and choose "use same settings as incoming server". If your ISP blocks 465, try 587, or switch to mobile data and test.

What should I enter as the username?

At almost all hosting providers the username is the full email address, not just "name": [email protected]. The password is the email account's password — do not confuse it with your hosting/panel password.