Warm up your Rejoiner sending domain
Warmy sends and engages with human-like conversations from your domain, so Gmail, Outlook and Yahoo learn to trust your campaigns before your next Rejoiner send.

Warmy connects to your Rejoiner sending domain to warm it up automatically, validate SPF, DKIM and DMARC, monitor reputation and blocklists, and show exactly where your campaigns land across Gmail, Outlook and Yahoo, before you press send.
Connects To Rejoiner In Under 25 Seconds | No Credit Card Required





The platform’s warmup processes make sure that our cold emails don’t bounce into spam filters. It also makes use of AI behavior tracking as we’re sending which is great for campaigns scaling. It’s also really valuable to be able to track open rates and responses.


No code, no migration, no change to how your team works in Rejoiner. Three clicks and Warmy starts protecting the domain your campaigns are sent from.
Choose Rejoiner from the provider list inside Warmy - no developer, no API tinkering.
Paste the sending address Rejoiner uses. Warmy checks SPF, DKIM and DMARC instantly.
Warm-up, inbox-placement tests and reputation monitoring begin on the same day.
Rejoiner sends the campaign. Warmy makes sure it reaches the inbox.
Warmy sends and engages with human-like conversations from your domain, so Gmail, Outlook and Yahoo learn to trust your campaigns before your next Rejoiner send.

Seed-list tests place your real Rejoiner template in live mailboxes and show inbox, promotions or spam for every provider - before you press send.

Continuous checks on SPF, DKIM, DMARC, blocklists and Google Postmaster data, with alerts the moment your Rejoiner domain starts slipping.

Rejoiner authentication
Rejoiner combines lifecycle email software with managed strategy. Gmail, Yahoo and Microsoft require authenticated email from bulk senders, so a authenticated sending domain with valid SPF, DKIM and DMARC is the baseline for reaching the inbox.
| Protocol | Purpose | Typical record | What it verifies |
|---|---|---|---|
| SPF | Authorizes sending infrastructure | TXT record on the sending domain | The sending server |
| DKIM | Adds a cryptographic signature | CNAME records provisioned by Rejoiner | The message and the signing domain |
| DMARC | Defines alignment and failure policy | TXT record at _dmarc | The visible From domain |
Record names and values differ per account. Always copy them from your own Rejoiner screen rather than from a generic example.
Why placement drops
Authentication only proves who sent the message. Placement depends on reputation, engagement and list quality - and Rejoiner senders hit a few specific problems.
Cart-abandonment flows send to buyers who may not remember the brand.
Managed programs launch fast, often on an unwarmed subdomain.
Revenue depends on a handful of high-frequency flows reaching the inbox.
Passing SPF, DKIM and DMARC confirms authentication, but it does not reveal where your campaigns actually land. Warmy helps Rejoiner senders test inbox placement across major providers, monitor domain reputation, identify blocklist issues and detect authentication problems before a campaign is sent.
See the inbox, promotions and spam split per provider before you press send.
Track reputation, blocklists and authentication changes continuously.
Build reputation on a new Rejoiner sending subdomain with human-like activity.
Certified specialists review your setup and prioritize what to fix first.
Keep going
Last reviewed August 2026 by Daniel Shnaider, Warmy Co-Founder, email deliverability specialist, for Rejoiner senders.
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