DirectAdmin runs Exim for sending and Dovecot for mailboxes, with Roundcube as webmail. Creating an address takes a minute; getting it to work reliably in a phone or desktop client, and getting the messages it sends delivered rather than junked, takes a little more. This post walks through all of it from the user's side of the panel.
Create the mailbox
At User Level, open E-mail Manager → E-mail Accounts and click Create Account. Three fields matter:
- Username is the part before the
@; the domain is chosen from the dropdown if the account has more than one. - Password: use the generator. The panel will not show it again afterwards, so copy it now.
- Quota in MB. Zero means unlimited, which on a shared server is a bad idea because one forgotten mailbox can fill the account's disk allowance. 1024 or 2048 is a sane default for a person; 10240 for a shared inbox that keeps everything.
There is also a daily Send Limit, inherited from the package. Leave it; an account that genuinely sends bulk mail should use a transactional service anyway.
After saving, DirectAdmin shows a summary with the mail server settings for that address. Everything below is on that screen too, but people close it and then search for it.
Webmail
Roundcube is at https://server1.example.com/roundcube, where the hostname is the server's own name, which carries a valid certificate from install. It also answers on https://mail.example.com/roundcube, without a certificate warning only if mail.example.com is on the domain's Let's Encrypt certificate. Log in with the full address as the username.
Roundcube is enough for occasional use and for checking that a mailbox works before you spend time on a client. Settings → Identities sets the display name and signature.
Settings for iPhone, Outlook and Gmail
Use these regardless of the client:
| Setting | Value |
|---|---|
| Username | the full address, alice@example.com |
| Incoming server | mail.example.com, IMAP, port 993, SSL/TLS |
| Outgoing server | mail.example.com, SMTP, port 587 with STARTTLS (or 465 with SSL/TLS) |
| Outgoing authentication | yes, same username and password |
POP3 on 995 also exists, but IMAP keeps the phone, the laptop and webmail in sync, so use it.
On iPhone, go to Settings → Mail → Accounts → Add Account → Other → Add Mail Account. Enter name, address and password; when it asks for servers, choose IMAP and fill both server fields with the values above. iOS will try SSL automatically.
In Outlook, choose Advanced options → Let me set up my account manually → IMAP, then enter the ports and encryption explicitly. Outlook's guess at "mail.example.com" is usually right, but its guess at STARTTLS on 587 is not always, so set it.
In Gmail on the web, Settings → Accounts and Import → Check mail from other accounts (POP3 only, so Gmail fetches rather than syncs) and Send mail as → Add another email address, with SMTP 587 and TLS. Gmail sends a verification code to the address, so have Roundcube open.
The one recurring failure is the certificate. mail.example.com must point to the server in DNS and be on the domain's certificate, otherwise every client warns that the name does not match. If it is not on the certificate, use the server hostname server1.example.com as both incoming and outgoing server instead; it always has a valid certificate and the mailbox is the same.
Forwarders, autoresponders and catch-all
E-mail Manager → Forwarders sends a copy of everything arriving at one address to another, local or external. A forwarder does not need a mailbox: sales@example.com → alice@example.com works without creating sales. If you want both a copy kept and a forward, create the mailbox and then the forwarder with the same name.
Autoresponders reply to every sender once, with a reply interval so two autoresponders do not loop. Vacation Messages is the same idea tied to a date range.
Catch-All decides what happens to mail sent to addresses that do not exist under the domain. Leave it on Fail, which rejects at SMTP time. Delivering catch-all to a mailbox means collecting every dictionary attack the domain receives, and "Ignore" silently discards, which hides typos from senders.
SPF, DKIM and DMARC
Deliverability depends on three DNS records, and DirectAdmin handles two of them for you.
SPF is created with the domain: a TXT record v=spf1 a mx ip4:203.0.113.10 ~all in the zone, listing the server. Check it under Account Manager → DNS Management; if the domain's DNS is hosted elsewhere, copy it there.
DKIM needs enabling once per domain. On DNS Management there is an Enable DKIM button when the administrator has turned DKIM on server-wide. Clicking it generates the key, adds the x._domainkey TXT record, and Exim starts signing. Again, if DNS is external, copy that record across, it is long and must be copied exactly.
DMARC the panel does not add. Create a TXT record named _dmarc with the value v=DMARC1; p=none; rua=mailto:dmarc@example.com to begin with, then tighten to p=quarantine once the reports show only your mail passing. What each record means and how to read the reports is in SPF, DKIM and DMARC explained, and editing the records themselves is covered in managing DNS records in DirectAdmin.
Where the mail actually lives
Messages are in /home/<user>/imap/<domain>/<account>/Maildir/, and the hashed passwords in /etc/virtual/<domain>/passwd. A mailbox reporting full after you deleted everything usually has a Trash folder that still holds it all; empty it in Roundcube.
On a VPSPioneer managed VPS with DirectAdmin we set up the server's mail hostname and certificate at install, so the settings above work the first time.