Warmerly
Gmail and Google Workspace, Outlook and Microsoft 365, Zoho, Namecheap Private Email, and custom SMTP and IMAP.
Warmerly
Mailwarm
One-to-one · Supported mailboxes
Supported mailboxes
One row, in depth: what each tool does, the verified numbers, and who each suits.
Mailwarm details read from its pricing page, home page, features page, SMTP warmup page and about page on 21 October 2026.
Warmerly
Gmail and Google Workspace, Outlook and Microsoft 365, Zoho, Namecheap Private Email, and custom SMTP and IMAP.
Mailwarm
Gmail, Google Workspace, Microsoft 365, Outlook, Yahoo, Zoho and SMTP relays such as SendGrid, with no IMAP access needed.
The short answer
Supported mailboxes, in one look.
Warmerly connects Gmail and Google Workspace, Outlook and Microsoft 365, Zoho, Namecheap Private Email and custom SMTP and IMAP. Mailwarm names more providers: Gmail, Google Workspace, Microsoft 365, Outlook, Yahoo, Zoho and several SMTP relays, and says it needs no IMAP access. Last checked 22 October 2026.
MailwarmMailwarm ahead on this row
Gmail, Google Workspace, Microsoft 365, Outlook, Yahoo, Zoho and SMTP relays such as SendGrid, with no IMAP access needed.
The picture
Drawn side by side.
What you can connect
As each company lists it
WarmerlyMailwarm
Five presets and custom SMTP
- Gmail and Google Workspace
- Outlook and Microsoft 365
- Zoho Mail
- Namecheap Private Email
- Custom SMTP and IMAP
Providers and relays, no IMAP
- Gmail, Outlook, Yahoo, Zoho
- SendGrid, Mailgun, Amazon SES, Postmark
- No IMAP access needed
Mailwarm names more providers. Warmerly connects over SMTP and IMAP settings.
How Warmerly does it
Warmerly, in detail.
Five connection presets, with custom SMTP and IMAP for other hosts.
01
Presets
The add-mailbox wizard has presets for Gmail and Google Workspace, Outlook and Microsoft 365, Zoho Mail, Namecheap Private Email, and custom SMTP and IMAP.
Warmerly product, checked 21 October 2026
02
How you connect
Gmail and Google Workspace connect with an app password. Microsoft connects through sign-in.
Warmerly product, checked 21 October 2026
03
IMAP and SMTP
Mailboxes connect over SMTP and IMAP settings, which the connection test checks.
Warmerly product, checked 21 October 2026
04
Provider caps
Daily warmup quota is held to 40 on Gmail, 30 on Outlook and 25 on Zoho.
Warmerly product, checked 21 October 2026
05
Gmail and Google Workspace use an app password
Warmerly asks for a Google app password, with 2-Step Verification turned on first. The wizard links to the Google page that creates one. On a Workspace account the setting can be hidden by an admin, and the help centre covers that case.
Warmerly product, checked 21 October 2026
06
Microsoft signs in with one click
Outlook, Microsoft 365, Outlook.com and Hotmail connect through Microsoft sign-in. Some Microsoft 365 organisations switch authenticated SMTP off, and then an admin has to enable it.
Warmerly product, checked 21 October 2026
07
Zoho, Namecheap and others connect by hand
Zoho Mail and Namecheap Private Email have presets with host and port filled in. IONOS, Hostinger and others use the custom SMTP and IMAP preset with a host and port table in the guides.
Warmerly product, checked 21 October 2026
08
Both SMTP and IMAP are tested
The setup form shows Sending (SMTP) and Reading replies (IMAP) separately, so you can see which failed. A mailbox cannot be saved unless both work.
Warmerly product, checked 21 October 2026
09
Provider caps on warmup
The daily quota is held to 40 on Gmail, 30 on Outlook, 25 on Zoho and 50 on Namecheap and custom, whatever the ramp would otherwise allow.
Warmerly product, checked 21 October 2026
10
Hosted mailboxes
OneMail mailboxes are hosted by Warmerly, so there is no password to enter. They are used through the Warmerly inbox and API, and no external IMAP or SMTP login is given for them today.
Warmerly product, checked 21 October 2026
How Mailwarm does it
Mailwarm, in detail.
A long list of providers and relays, with no IMAP access needed.
01
Mailbox providers
Google Workspace and Gmail, Microsoft 365 and Outlook, Yahoo and Zoho.
mailwarm.com/pricing · read 21 October 2026
02
SMTP platforms
AWS, SendGrid, Mailgun and Other, and its SMTP page names Amazon SES, Postmark and custom SMTP.
mailwarm.com/smtp-warmup · read 21 October 2026
03
No IMAP access
Its SMTP page says warmup works without IMAP access and never needs permission to read your inbox.
mailwarm.com/smtp-warmup · read 21 October 2026
04
OAuth connections
Its features page says OAuth connections are secure, with no password sharing.
mailwarm.com/features · read 21 October 2026
05
IP warmup
It has a separate page for dedicated IP warmup.
mailwarm.com · read 21 October 2026
06
Provider list on its pricing page
Gmail and Google Workspace, Microsoft 365 and Outlook, and other SMTP-based platforms. Its icons show Google, Outlook, Yahoo, AWS, SendGrid, Mailgun, Zoho and Other.
mailwarm.com · read 22 October 2026
07
Separate pages by provider
It has pages for SMTP, Gmail, Microsoft and Yahoo warmup and for IP warmup, each describing its own setup.
mailwarm.com · read 22 October 2026
08
Provider choice
It says you can choose warmup providers: Gmail, Outlook, Microsoft 365, Yahoo and SMTP, and lists provider-level warmup as a feature of every plan.
mailwarm.com/pricing · read 22 October 2026
09
Setup
It says setup takes about 2 minutes: link an email account and start the warmer.
mailwarm.com · read 22 October 2026
10
Works beside any sender
Its tool page says it is standalone, so you connect the same inbox to Mailwarm and to your sending tool, and turn off any built-in warmup in the other tool to avoid doubling volume.
mailwarm.com/email-warmup-tool · read 22 October 2026
11
SMTP relays named
Its tool page names SendGrid, Mailgun, Amazon SES, Postmark and custom SMTP.
mailwarm.com/email-warmup-tool · read 22 October 2026
What Mailwarm does not say
We looked, and found no statement on these. That is about its published pages only, not about the product.
- How a Yahoo mailbox is connected
- Whether it supports IMAP-only hosts
Where the sources disagree
We report each version rather than pick one.
- Its SMTP page says week 1 is warmup traffic only and also lists 10 to 20 real emails a day; it does not say which is meant.
The numbers
Only what we could verify.
| Measure | Warmerly | Mailwarm |
|---|---|---|
| Supported mailboxes | Gmail and Google Workspace, Outlook and Microsoft 365, Zoho, Namecheap Private Email, and custom SMTP and IMAP. | Gmail, Google Workspace, Microsoft 365, Outlook, Yahoo, Zoho and SMTP relays such as SendGrid, with no IMAP access needed. |
| Named providers | Gmail, Outlook, Zoho, Namecheap, custom | Gmail, Outlook, Yahoo, Zoho, SMTP relays |
| IMAP access needed | Yes, SMTP and IMAP settings | No, as its SMTP page states |
| SMTP relays named | Custom SMTP and IMAP | SendGrid, Mailgun, Amazon SES, Postmark |
| Yahoo mailboxes | Not a preset | Named on its pages |
| Zoho mailboxes | Preset | Named on its pages |
| Namecheap Private Email | Preset | Not named on the pages we read |
| Hosted mailboxes | OneMail, outside the plan count | Not stated |
| Daily provider caps on warmup | 40 Gmail, 30 Outlook, 25 Zoho | Up to 50, 200 or 500 by tier |
In practice
What it means for you.
Our reading of the facts above. Not a promise, and not the only reasonable reading.
Mailwarm is ahead on breadth
If you warm a relay such as SendGrid or Amazon SES, or you do not want to give IMAP access, Mailwarm names those cases and Warmerly does not.
Your sending tool decides a lot
If you send from Gmail, Google Workspace or Microsoft 365, both tools cover you. If you send through a relay such as SendGrid or Amazon SES and want it warmed, Mailwarm is the one that names it.
Using an app password
On Warmerly a Gmail mailbox needs an app password. If your Workspace admin has hidden that setting, you will need them to enable it. Mailwarm's pages say its warmup needs no IMAP access, which changes what you must give.
Provider caps on Warmerly
A Gmail mailbox on Warmerly is held to 40 warmup emails a day even when the ramp would allow 50, because Gmail is the strictest provider here. That is a safety setting, not a fault.
A mixed estate
A team with Gmail, Outlook and Zoho mailboxes can connect all three kinds on Warmerly. A team that also uses Yahoo or a relay needs Mailwarm for those mailboxes.
When a connection fails
Warmerly's help centre lists each message the setup form can give and what to do, from wrong password to wrong port. Mailwarm's pages do not publish a similar table.
Who it suits
Pick the one that fits.
Warmerly
Warmerly is the better fit if
- Your mailboxes are Gmail, Google Workspace, Microsoft 365 or Zoho
- Your mailboxes are on Google Workspace, Microsoft 365, Zoho or Namecheap
- You want a table of connection errors and fixes
- You want hosted mailboxes that sit outside the plan count
Mailwarm
Mailwarm is the better fit if
- You warm an SMTP relay or a Yahoo mailbox
- You do not want to give IMAP access
- You warm a Yahoo mailbox or an SMTP relay
- You prefer not to share IMAP access
- You want a page for each provider's warmup
Questions
Which mailboxes does Mailwarm support?
Google Workspace and Gmail, Microsoft 365 and Outlook, Yahoo, Zoho and SMTP platforms such as SendGrid, Mailgun, Amazon SES and Postmark. It says it needs no IMAP access.
Does Warmerly support Yahoo?
There is no Yahoo preset. The custom SMTP and IMAP preset can be used for other hosts, but we do not list Yahoo as a supported provider.
Does Mailwarm need IMAP access?
Its pages say no. The pricing table lists No IMAP access required on every tier.
Can I use Warmerly with SendGrid or Amazon SES?
Those relays are not named in our wizard. The custom SMTP and IMAP preset connects a mailbox, but those relays are not listed as supported providers.
Sources
Mailwarm pages were read on 21 October 2026. Plans and wording change, so check the vendor's own page before you decide. Warmerly details come from the product as it runs today.
More features
See it on your own mailbox.
Connect a mailbox. Warmerly runs alongside whatever you send from now, so you can compare before you move anything.
Free plan, no card. Paid plans: 7-day trial, first charge on day 8.