> ## Documentation Index
> Fetch the complete documentation index at: https://docs.migma.ai/llms.txt
> Use this file to discover all available pages before exploring further.
# Email Deliverability Best Practices
> Authenticate your domain, keep lists clean, reduce complaints, and test emails before sending.
Email deliverability is shared between your sending domain, audience quality, message content, and mail provider. Migma helps with domain setup, validation, suppression, rendering checks, and preflight review, but inbox placement is never guaranteed.
Use this page as an operating checklist before important sends.
Migma is built for permission-based email. Do not use Migma for cold outreach, purchased lists, scraped contacts, or people who did not ask to hear from you. See [Permission-based sending](/get-started/what-you-can-send).
## Delivery Readiness
Check these four areas before any high-volume or important campaign.
| Area | Ready when | If not ready |
| ---------- | ------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------- |
| Permission | Recipients clearly opted in for this kind of email | Review [sending rules](/get-started/what-you-can-send) and narrow the audience |
| Domain | SPF, DKIM, DMARC, and MAIL FROM are verified | Finish [Add Sending Domain](/sending-domains/add-domain) and resolve [Verification Issues](/sending-domains/verification-issues) |
| Audience | Bounces, complaints, unsubscribes, invalid contacts, and risky addresses are excluded | Clean the list with [Deliverability & Validation](/audience/deliverability) and [Suppression List](/sending-domains/suppression-list) |
| Email | Links, rendering, content, compliance basics, and spam-risk signals pass review | Run [Email Preflight](/email-editor/email-preflight), fix red items, and re-check |
***
## Start With Consent
Mailbox providers look at recipient behavior. People who expected your email are more likely to open, click, reply, or ignore it without complaint. People who did not expect it are more likely to bounce, unsubscribe, or mark it as spam.
Before importing or sending to a list, confirm:
* Contacts opted in through a form, checkout flow, account setting, event registration, or another clear consent path.
* The email type matches the consent they gave, such as newsletter, lifecycle, product update, or transactional.
* Suppressed, bounced, complained, and unsubscribed contacts remain excluded.
* Segment criteria match the message. Do not send broad campaigns to people with weak or stale intent.
Purchased, rented, scraped, guessed, or cold outreach lists damage domain reputation and are not allowed in Migma.
Related: [GDPR newsletter consent](/compliance/gdpr-newsletter-consent), [CAN-SPAM checklist](/compliance/can-spam-checklist), [CSV Upload](/audience/csv-upload).
***
## Authenticate Your Sending Domain
Authentication proves that your email provider is allowed to send mail for your domain. Major inbox providers expect authenticated mail, and bulk senders should treat SPF, DKIM, and DMARC as required.
| Record | What it does | Where to set it up |
| --------- | ----------------------------------------------------------------------------- | ------------------ |
| SPF | Authorizes sending servers for your domain | DNS provider |
| DKIM | Signs messages so inbox providers can verify they were not changed in transit | DNS provider |
| DMARC | Tells receivers how to evaluate mail that fails SPF or DKIM alignment | DNS provider |
| MAIL FROM | Aligns bounce handling with your sending domain | DNS provider |
In Migma:
Go to **Sending Domains** and add the domain or subdomain you want to send from.
Add each record at your DNS provider. If you use Cloudflare, keep email authentication records **DNS only**.
Return to Migma and click **Check DNS** until the domain is verified.
Use [Add a Sending Domain](/sending-domains/add-domain) for the full setup flow. If a record does not verify, see [Verification Issues](/sending-domains/verification-issues).
***
## Keep Complaint Rate Low
User-reported spam is one of the clearest negative signals. [Google's sender guidelines](https://support.google.com/mail/answer/81126?hl=en) recommend keeping user-reported spam below 0.1% and preventing it from reaching 0.3% or higher. Migma's own domain health thresholds are stricter for managed domains because shared infrastructure needs tighter controls.
To reduce complaints:
* Send only to contacts with clear consent.
* Set expectations at signup about content and frequency.
* Use a recognizable sender name and a monitored reply address.
* Make the subject line match the email body.
* Avoid sending too often to inactive contacts.
* Make unsubscribe easy before people reach for the spam button.
Track domain status in [Domain Health](/sending-domains/domain-health) and campaign results in [Track Results](/campaigns/track-results).
***
## Make Unsubscribe Easy
Marketing and promotional email should include a visible unsubscribe or preference link in the message body. Large senders also need one-click unsubscribe headers for [Gmail](https://support.google.com/mail/answer/81126?hl=en) and [Yahoo](https://senders.yahooinc.com/best-practices/) inbox requirements.
Good unsubscribe behavior:
* Keep the unsubscribe or preference link visible in the footer.
* Do not require login to opt out.
* Honor opt-outs quickly. Migma suppression flows are designed to apply immediately to marketing sends.
* Offer topic or frequency choices when that helps subscribers stay on the right list.
* Never send marketing campaigns to suppressed contacts.
Related: [Preference Center](/audience/preference-center), [Suppression List](/sending-domains/suppression-list), [CAN-SPAM Checklist](/compliance/can-spam-checklist).
***
## Warm New Domains Gradually
New domains have little or no reputation. Sending a large campaign immediately can look suspicious, even when the audience opted in.
Use warming when:
* The domain or subdomain is new.
* You are moving from one email service provider to another.
* You have not sent consistent volume recently.
* You plan to increase volume significantly.
During warming:
* Start with engaged subscribers first.
* Send consistently within the daily limit.
* Pause broad campaigns if bounces or complaints rise.
* Avoid sudden jumps in volume or frequency.
See [Domain Warming](/sending-domains/domain-warming) for Migma's configurable warming plan and safety thresholds.
***
## Keep the List Clean
List quality has more impact than small copy tricks. Bounces, disposable addresses, role inboxes, spam traps, and long-inactive contacts all weaken reputation.
Use Migma to:
* Validate new contacts during import.
* Re-validate stale subscribed contacts.
* Exclude risky addresses from sends.
* Review skipped recipients after each campaign.
* Keep bounces, complaints, unsubscribes, and manual blocks suppressed.
For high-stakes campaigns, build a segment from recently engaged, valid contacts first. Then expand carefully after you confirm healthy delivery, bounce, complaint, open, and click signals.
Related: [Deliverability & Validation](/audience/deliverability), [Skipped Recipients](/campaigns/skipped-recipients), [Suppression List](/sending-domains/suppression-list).
***
## Send Relevant, Readable Email
Content still matters, but modern filtering is not about one magic word. Inboxes evaluate whether the message looks legitimate, matches recipient expectations, renders correctly, and gets healthy engagement.
Before sending, review:
* **Subject line**: truthful, specific, and aligned with the email body.
* **Sender identity**: recognizable brand or person, not a misleading alias.
* **Layout**: readable on mobile, clear hierarchy, no image-only email.
* **Links**: relevant destinations, no broken URLs, no unnecessary redirect chains.
* **Images**: compressed, useful alt text, and enough live text if images are blocked.
* **Accessibility**: readable contrast, descriptive link text, and scannable structure.
* **Dark mode**: text, logos, buttons, and backgrounds stay legible.
Use a simple test: if a recipient opened this email without images, would they still understand who sent it, why they got it, and what to do next?
For rendering details, see [Email Client Compatibility](/email-editor/client-compatibility).
***
## Run Preflight Before Important Sends
Preflight checks the email Migma will actually send or export. Use it before production campaigns, especially after editing copy, links, images, or layout.
Open the email draft or conversation you plan to send.
Click **Compatibility Check** in the editor toolbar.
Check rendering previews, CSS compatibility, links, spelling, compliance basics, and deliverability score.
Use **Fix with AI** where helpful, then run Preflight again before sending or exporting.
Preflight does not replace good list quality or domain reputation. It helps catch issues in the email itself before subscribers see them.
***
## Monitor After Sending
Deliverability work continues after send. Watch each campaign and domain over time so small issues do not become reputation problems.
| Signal | What to watch | Where |
| ------------------ | -------------------------------------------------------------- | --------------------------------------------------- |
| Bounce rate | Invalid, stale, or unreachable addresses | [Domain Health](/sending-domains/domain-health) |
| Complaint rate | People marking mail as spam | [Domain Health](/sending-domains/domain-health) |
| Skipped recipients | Suppressed, invalid, risky, or unsubscribed contacts held back | [Skipped Recipients](/campaigns/skipped-recipients) |
| Opens and clicks | Whether recipients are engaging | [Track Results](/campaigns/track-results) |
| Unsubscribes | Frequency, targeting, or expectation mismatch | [Track Results](/campaigns/track-results) |
If performance drops, narrow the next send to recent engagers, clean or re-validate the audience, review signup expectations, and check domain health before increasing volume again.
***
## Pre-Send Checklist
Before an important campaign:
* [ ] Audience has clear permission for this email.
* [ ] Suppressed, bounced, complained, and unsubscribed contacts are excluded.
* [ ] Sending domain is verified with SPF, DKIM, DMARC, and MAIL FROM.
* [ ] New domain is warming or already has steady sending history.
* [ ] Subject line matches the message.
* [ ] From name and reply-to are recognizable and monitored.
* [ ] Unsubscribe or preference link is visible and working.
* [ ] Email has enough live text if images are blocked.
* [ ] Mobile and dark mode previews are readable.
* [ ] Links work and use relevant destinations.
* [ ] Email Preflight has been run after final edits.
* [ ] Test email has been reviewed in a real inbox.
***
## Related Pages
Permission-based sending rules for Migma.
Set up and verify DNS records.
Validate contacts and exclude risky addresses.
Review rendering, links, content, compliance basics, and deliverability risk.
Monitor bounce and complaint rates.
Review U.S. commercial email requirements.