Email Deliverability Best Practices

Why deliverability is a discipline

Getting email sent and getting it into the inbox are two different things. Inbox providers score every sender on authentication, list quality, and engagement. StretchMail gives you the tools to score well; this guide is how to use them.

1. Authenticate your domain

The foundation is a verified sending domain. StretchMail's DNS records do the heavy lifting:

• SPF authorizes StretchMail to send for you.
• DKIM signs every message so receivers can prove it wasn't tampered with.
• DMARC tells receivers how to treat mail that fails the above.

Until all four (verification, SPF, DKIM, DMARC) read active on the Domains tab, expect spam-foldering. Verify first — see Verifying your sending domain.

2. Only mail people who want it

StretchMail enforces this for you, but the intent has to be yours:

• Only subscribed contacts are emailed. Keep statuses honest.
• The suppression list is always excluded — anyone who opts out is never contacted again, automatically.
• Never import purchased or scraped lists. Cold lists generate spam complaints that damage your domain for everyone.

3. Keep your lists clean

List hygiene is the single biggest lever after authentication:

1. Remove hard bounces. Use the Reports send log to find failed addresses and delete them.
2. Unsubscribe, don't delete, opt-outs. Setting a contact to unsubscribed preserves the record while stopping mail.
3. Re-verify old lists. A list you haven't mailed in a year is a deliverability risk — send a gentle re-engagement first.
4. Watch your Segments. A rising unsubscribed share or lots of role addresses (info@, admin@) signals trouble.

4. Warm up gradually

A brand-new domain that suddenly sends thousands of emails looks like a spammer. Ramp up:

1. Start with your most engaged contacts and small sends.
2. Increase volume over days and weeks as opens and clicks prove engagement.
3. Keep a steady cadence rather than sending in unpredictable bursts.

5. Earn engagement

Providers reward mail people open, read, and reply to:

• Write honest subject lines — no bait-and-switch. It protects your open rate and your reputation.
• One clear call to action beats a wall of links.
• Send a plain-text-friendly message. StretchMail auto-generates the text version; keep your content readable without images.
• Test before every send to the inbox most of your audience uses.

Worked example

Payne Coaching Co. launches a new domain:

1. Beau verifies paynecoaching.com end to end (all records active).
2. First campaign goes to just his 45 most engaged clients, not a bought list.
3. He checks Reports, removes one bounced address, and confirms a 47% open rate.
4. Over the next month he grows sends steadily, keeps the subject lines honest, and never re-mails the two clients who unsubscribed.

Six weeks in, his mail reliably lands in the primary inbox.

Tips

• Verify, then warm up, then scale — in that order.
• A clean small list outperforms a big dirty one. Every bounce and complaint costs you.
• Match your "From" name and domain to what recipients expect to see.
• Monitor open rate as a health signal. A sudden drop often means a deliverability problem, not a content one.

FAQ

Do I need DMARC?
Yes — modern inbox providers increasingly require it, and StretchMail generates it for you. Publish it.

Can I email people who never opted in?
Don't. It generates complaints that harm your domain for all future sends.

Why did a previously good campaign start hitting spam?
Usually list quality (stale addresses, complaints) or a change to your DNS. Re-check Domains and clean your list.

Troubleshooting

• Mail lands in spam. Confirm all DNS records are active, your list is opt-in and clean, and you're not sending from a cold domain too fast.
• High bounce rate. Your list is stale or low-quality — prune failed sends and re-engage carefully.
• Rising unsubscribes. Reduce frequency or improve relevance; check your Segments for audience mismatch.