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Make sure your outreach emails land in the inbox, not spam. This guide covers domain setup, warm-up, volume and content.
1. Authenticate your domain#
| Record | What it does | Where to set it |
|---|---|---|
| SPF | Lists the servers allowed to send for your domain | DNS TXT record, for example v=spf1 include:_spf.google.com ~all for Google Workspace |
| DKIM | Cryptographically signs your emails | Generated in your email admin, added as a DNS TXT or CNAME record |
| DMARC | Tells receivers what to do with failing mail | DNS TXT at _dmarc.yourdomain.com, for example v=DMARC1; p=none; rua=mailto:dmarc@yourdomain.com |
Google and Yahoo require SPF, DKIM and DMARC for bulk senders. Check your setup with a free tool such as MXToolbox or mail-tester.com.
Where to find DKIM:
- Google Workspace: Admin console → Apps → Google Workspace → Gmail → Authenticate email
- Microsoft 365: Microsoft Defender → Email & collaboration → Policies → Email authentication settings → DKIM
- Zoho / others: Mail admin → Domains → Email configuration
2. Use a secondary domain#
Send cold outreach from a domain like getacme.com or tryacme.com instead of acme.com. If something goes wrong, your main domain, and your team's everyday email, stays safe.
- Redirect the secondary domain to your main website.
- Set up SPF, DKIM and DMARC on it too.
- Create real mailboxes with real names, for example
priya@getacme.com.
3. Warm up new mailboxes#
| Week | Emails / day per mailbox |
|---|---|
| 1 | 5–10 (to people you know) |
| 2 | 15–25 |
| 3 | 25–40 |
| 4+ | Up to 50 |
In Prosyo, set Emails / day on the campaign's Sending & safety tab. The Cautious preset starts at 25.
4. Keep volume per mailbox low#
Stay under about 50 cold emails per mailbox per day. For more volume, add mailboxes rather than pushing one harder:
- Extra SMTP/IMAP seat: $2/month per mailbox. See Add-ons.
- Split the list across campaigns, each with its own mailbox.
5. Write emails that land#
| Do | Don't |
|---|---|
| Plain text | Heavy HTML, images, attachments |
| Under 120 words | Long paragraphs |
| One link at most (or none in email 1) | Several links or link shorteners |
A natural subject line: {{company_name}} + outbound | "FREE", "Act now", ALL CAPS, lots of !!! |
| Personalization that's real | Obvious mail-merge ("Dear {{first_name}}") |
| Replies in the same thread for follow-ups | A new subject every time |
6. Keep your list clean#
- Only email addresses from a real source. Prosyo never guesses emails.
- Verify addresses from data providers before importing.
- Remove bounces and people who ask to stop. Set them to Do not contact.
7. Watch the signals#
| Signal | Healthy | Act if |
|---|---|---|
| Bounce rate | Under 2% | Over 3%: clean your list |
| Reply rate | 2%+ | Under 1%: check spam placement and targeting |
| Spam complaints | ~0 | Any: slow down, review copy and targeting |
8. Compliance#
Follow the laws where your recipients are, such as CAN-SPAM, GDPR, PECR and CASL. Identify yourself, have a legitimate reason to contact them, and honor opt-outs immediately. See Responsible outreach.
Quick checklist#
- SPF, DKIM and DMARC pass
- Secondary sending domain
- Mailbox warmed for 2+ weeks
- Under 50 cold emails per mailbox per day
- Plain text, one link at most, under 120 words
- Clean, verified list
- Opt-outs set to Do not contact
