Compare the Top SMTP Services as of November 2025

What are SMTP Services?

SMTP services and SMTP relay services enable organizations to send emails, including bulk emails to customers and users from their website. SMTP service providers provide an SMTP server that can be hosted or used on-premise so websites can send emails and ensure high deliverability of emails and mass email campaigns. Mail transfer agent (MTA) services are part of SMTP services. Compare and read user reviews of the best SMTP services currently available using the table below. This list is updated regularly.

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    DuoCircle

    DuoCircle

    DuoCircle

    Reliable and secure email hosting services for SMB and Enterprise. Safely processing over 100 million emails per month for our customers. Enhanced gateway security and filtering, inbound email security, email service backup and outbound SMTP using a new high quality infrastructure for top quality results that our customers deserve. Products include, Secure email gateway, email backup MX, email forwarding, outbound SMTP and more. DuoCircle protects against phishing attack with Link Click Protection, a part of the Advanced Threat Defense Suite. You’re covered with Link Click Protection even if site content changes between clicks. You get total protection from phishing and your confidential corporate information is secured because your employees are simply prevented from visiting sites that misuse such information. You get instant feedback in the form of an alert when a suspicious link is about to be visited.
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