SecondStreet email service provider (ESP)

According to Live Direct Marketing's daily Tranco top-1M scan (July 13, 2026), SecondStreet is the email service provider (ESP) for 258 domains — 0.04% of 617,702 SPF-publishing domains. Detection method: include: mechanisms in the SPF record.

Key facts

SecondStreet is an email service provider that manages outbound mail delivery for organisations worldwide. Its presence in email infrastructure is most visible through SPF records, where client domains include SecondStreet's mechanisms to authenticate their outbound mail.

SecondStreet's deployment skews toward smaller and mid-market organisations rather than the largest global brands, with particularly strong concentration in the .com namespace. It is frequently found running alongside Google Workspace, indicating that many organisations separate their email functions—using Google for internal corporate mail while routing transactional, marketing, or other outbound mail through SecondStreet.

Where SecondStreet sits in the Tranco ranking

Tranco rank bandDomainsShare of its base
Top 1,00000.0%
Top 10,00000.0%
Top 100,0005220.2%
Top 1,000,00019676.0%
Unranked103.9%

Top-level domain split

TLDDomainsShare
.com24795.7%
.com.au31.2%
.net31.2%
.us10.4%
.cc10.4%
.hn10.4%
.news10.4%
.fm10.4%

What SecondStreet users also use

Cross-tabulated from the same daily snapshot — the other email services seen on the same 258 domains.

TypeServiceDomainsShare of SecondStreet users
MailboxGoogle Workspace12247.3%
MailboxMicrosoft 3657127.5%
MailboxMimecast166.2%
MailboxNetwork Solutions / Web.com93.5%
MailboxProofpoint72.7%
MailboxBarracuda62.3%
ESPAmazon SES3312.8%
ESPMailchimp207.8%
ESPEmsd1 (transactional)207.8%
ESPMimecast166.2%

SPF configuration and infrastructure awareness

SecondStreet is detected in mail infrastructure primarily through SPF include mechanisms, meaning any organisation using it for outbound mail must maintain accurate SPF records that reference SecondStreet's sending infrastructure. Misconfiguration or incomplete SPF policies can result in delivery failures, authentication rejections, or domain reputation damage. This risk is particularly acute for smaller organisations that may outsource email functions to third-party applications without fully understanding their mail routing path, inadvertently routing through SecondStreet without ensuring their SPF records account for it.

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

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Frequently asked questions

Should I test email deliverability against SecondStreet?

If a substantial share of your recipients are smaller or mid-market organisations using .com domains, understanding how SecondStreet handles authentication and delivery can be useful. For most senders, SecondStreet-specific testing is secondary to general best practices; prioritise it if you observe deliverability patterns that correlate with SecondStreet infrastructure.

How many domains use SecondStreet?

258 domains in the Tranco top-1M use SecondStreet 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 SecondStreet common enough to affect email deliverability testing?

SecondStreet 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 SecondStreet most?

SecondStreet's largest TLD is .com (95.7% of its domains); it appears across 8 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%)