Senders & Domains

Adding Senders

Senders are the mailbox accounts that actually send your campaign emails. You can create internal mailboxes (via the integrated mail server) or connect external SMTP accounts.

Internal Mailboxes (Recommended)

If you're using the integrated docker-mailserver (default setup), you can create mailboxes directly:

1

Add a verified domain first

You need at least one verified domain before creating internal senders.

2

Create the sender

Go to Senders → Add Sender. Select your domain and enter a prefix (e.g., alex creates alex@yourdomain.com).

3

Mailbox is auto-created

Cleanmails automatically creates the mailbox on docker-mailserver with a secure random password, configures SMTP and IMAP credentials, and tests the connection.

External SMTP Accounts

Connect any external email account (Gmail, Outlook, custom SMTP):

1

Click Add Sender → External

Select "External SMTP" mode.

2

Enter credentials

Provide:

  • Email — The full email address
  • Name — Display name for the From header
  • SMTP Host — e.g., smtp.gmail.com
  • SMTP Port — Usually 587 (STARTTLS) or 465 (SSL)
  • Username — Usually the email address
  • Password — App password (for Gmail, generate at myaccount.google.com)
  • IMAP Host (optional) — For reply detection
  • IMAP Port — Usually 993
3

Connection test

Cleanmails tests both SMTP and IMAP connections before saving. If SMTP fails, the sender is not created.

Password encryption

All sender passwords are encrypted with AES using your MASTER_KEY before storage. They are never exposed in API responses.

Sender Properties

PropertyDescription
Daily LimitMax emails per day (default: 50). Prevents over-sending.
Health Score0-100 reputation indicator. Decreases on bounces, increases on successful sends.
Warmup ModeWhen enabled, sender participates in warmup (not used for campaigns).
Statusready, warmup, or restricted
CooldownAuto-paused for 30 min after 3 consecutive errors

Sender Health

Health score changes:

  • Successful send: +1 (up to 100)
  • Soft bounce: -5
  • Hard bounce: -10 to -15
  • Permanent failure: -10

Senders with health below 20 are excluded from campaign assignment.

Cooldown system

After 3 consecutive errors, a sender is automatically put in cooldown for 30 minutes. This prevents hammering a broken connection and protects reputation.