MailPlus email service provider (ESP)

According to Live Direct Marketing's daily Tranco top-1M scan (July 13, 2026), MailPlus is the email service provider (ESP) for 222 domains — 0.04% of 617,702 SPF-publishing domains. Detection method: include: mechanisms in the SPF record.

Key facts

MailPlus is an email service provider identified across the internet through SPF include mechanisms in domain records. It appears most frequently among smaller and mid-market websites rather than among the largest global brands, clustering geographically in the .nl (Netherlands) region.

MailPlus is commonly observed running alongside Microsoft 365 in organizational mail stacks, suggesting a supplementary or hybrid role rather than a primary mail carrier. For deliverability analysts and email senders, this footprint pattern indicates that MailPlus reaches a specific—and relatively niche—segment of recipients, making targeted testing or reputation monitoring against it typically unnecessary unless dealing directly with organizations in that segment.

Where MailPlus sits in the Tranco ranking

Tranco rank bandDomainsShare of its base
Top 1,00000.0%
Top 10,00020.9%
Top 100,000167.2%
Top 1,000,00018683.8%
Unranked188.1%

Top-level domain split

TLDDomainsShare
.nl16373.4%
.com3214.4%
.eu62.7%
.org41.8%
.be41.8%
.co.uk31.4%
.de20.9%
.hr20.9%
.fr10.5%
.ro10.5%

What MailPlus users also use

Cross-tabulated from the same daily snapshot — the other email services seen on the same 222 domains.

TypeServiceDomainsShare of MailPlus users
MailboxMicrosoft 36514364.4%
MailboxUnknown / Other2913.1%
MailboxGoogle Workspace156.8%
MailboxSelf-Hosted83.6%
MailboxGeneric / unmatched (mx*.*)62.7%
MailboxMimecast41.8%
ESPMandrill2511.3%
ESPFlowmailer2511.3%
ESPSendGrid (Twilio)229.9%
ESPMailgun167.2%

MailPlus and Microsoft 365 hybrid configurations

MailPlus frequently appears in SPF records alongside Microsoft 365, typically indicating a hybrid mail setup where MailPlus handles specific mail flows or legacy routing whilst Microsoft 365 manages primary mail transport. This pattern suggests MailPlus may be deployed for transactional mail, regional relay, or domain transition scenarios. Deliverability troubleshooting involving MailPlus should account for this hybrid context: both mail paths need verification, and authentication or reputation issues may originate from either provider depending on which routes through which system.

See the full MailPlus data page (KPI cards, trend, sample domains) →

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Frequently asked questions

Should I test my mail delivery against MailPlus?

Testing against MailPlus is generally a low priority unless you have specific evidence that your recipients rely on it. Focus first on major ISPs and backbone providers; however, if you are sending to organizations in the Netherlands or know they operate a hybrid Microsoft 365 and MailPlus setup, monitoring both delivery paths is prudent.

How many domains use MailPlus?

222 domains in the Tranco top-1M use MailPlus as their email service provider (ESP) as of July 13, 2026 (0.04% of SPF-publishing domains), according to Live Direct Marketing's daily DNS scan.

Is MailPlus common enough to affect email deliverability testing?

MailPlus accounts for 0.04% of SPF-publishing domains in the top 1M. Whether you should seed a test mailbox there depends on how much of your audience it represents — the co-usage table above shows the services it appears alongside most.

Which countries or TLDs use MailPlus most?

MailPlus's largest TLD is .nl (73.4% of its domains); it appears across 14 TLDs in total.

Other email service provider (ESP)s

Amazon SES (6.21%)SendGrid (Twilio) (4.76%)Mailgun (4.11%)Zendesk (3.86%)Mailchimp (3.69%)Mandrill (3.36%)HubSpot (3.18%)Salesforce (2.62%)Mailjet (Sinch) (2.13%)Cloudflare Email Routing (1.80%)