Most WordPress sites send fewer than a few hundred emails a month: password resets, contact-form confirmations, the occasional WooCommerce order receipt. At that volume, a free tier from a dedicated SMTP provider is a better option than the host’s built-in mail() function, which sends unauthenticated mail from the shared hosting IP with no DKIM signature, no SPF alignment for the site’s domain, and no bounce or failure surface. For sites that fit inside the free thresholds, the cost of authenticated, monitored email is $0 in perpetuity. Configuring it also requires a dedicated SMTP plugin on the WordPress side and the supporting DNS records; How to set up email on WordPress walks the full end-to-end setup.
The category is smaller than aggregator listicles claim. Search for "free SMTP" and the results pad their counts with trials, sandboxes, and services that retired their free tier years ago. The honest list is short. This page covers every provider in nanoPost’s sending-service database with a $0 entry point and separates the permanent free plans from the time-limited or testing-only ones, because lumping them together is what makes most "free SMTP" lists useless.
For typical WordPress transactional volume, the default recommendation is SMTP2GO: 1,000 emails/month, no expiry, no branding, no marketing overhead. The rest of this page covers when something else is the better fit.
Permanent, trial, and sandbox: the distinction that matters
Not all $0 tiers behave the same way. Three categories exist, and conflating them produces decisions that fail in week nine.
Permanent free tiers have no documented expiry. Sign up, configure SMTP, send mail indefinitely within the published limits. The provider may change the terms in future, but the plan is positioned as ongoing free usage, not as evaluation.
Trial tiers offer $0 access for a fixed window. SendGrid’s 60-day trial is the canonical example: 100 emails/day for two months, then the free access ends. A site configured during the trial stops sending on day 61 unless it upgrades.
Testing sandboxes offer ongoing $0 access but explicitly prohibit production use. Postmark’s developer sandbox caps at 100 emails/month with no overages allowed; the documentation is clear that the sandbox exists to let developers verify their integration before paying, not to run a live site.
The roundup below groups providers accordingly. Trials and sandboxes appear in their own section so they do not get treated as alternatives to genuine permanent free plans. All eight providers, side by side:
Permanent free tiers
These five providers offer ongoing $0 access with no documented expiry and operate as transactional sending paths. Volume limits apply, but within those limits a WordPress site runs in production indefinitely without paying. MailPoet is also permanent and free, but it covers a different job; it gets its own section below.
SMTP2GO
The default. 1,000 emails/month with a 200/day cap, no credit card, no branding inserted into messages, no time limit. The free tier shares the reporting dashboard and the deliverability infrastructure with paid plans; it is a smaller allowance of the same product, not a deliberately crippled trial.
For a WordPress site sending password resets, form confirmations, and the occasional WooCommerce receipt, 1,000/month is comfortable. The 200/day cap matters only if the traffic clusters: a flash sale, a bulk subscriber notification, a contact form spike. Sites consistently bumping the cap have outgrown the free tier.
Where SMTP2GO’s free tier stops being the answer: sites that grow past 1,000/month, sites that want marketing automation alongside transactional, or sites that need dedicated IPs (Professional plan and above). The first paid tier is $10/month for 10,000 emails, which is the cleanest upgrade path in this list. For everything else, configure it in WP Mail SMTP or FluentSMTP, add the DKIM and SPF records, and stop thinking about it.
Brevo (Sendinblue)
300 emails per day, no monthly cap, no expiry. That is roughly 9,000 emails a month, well above what most WordPress sites need. No other permanent free tier in this list matches that daily throughput.
The catch is the shape of the platform. Brevo is a marketing-first product that handles A transactional email is the automated message a WordPress site sends in response to a single user action – a password reset, an order confirmation, a form receipt – addressed to the user who triggered it. Read full reference → as a secondary capability, and the free tier’s 300/day allowance is shared between marketing campaigns and transactional sends on the account. A site running both can find the day’s transactional headroom consumed by a campaign blast, with WooCommerce order confirmations queued or rejected as a result. For transactional-only use, the cap is generous; for combined transactional-and-marketing on a busy day, it is the constraint.
The right pick for sites that genuinely want both directions from one account, or for transactional-only sites with sustained volume above SMTP2GO’s 1,000/month but below the point where paying makes sense. The dashboard’s marketing features become noise for the second case; configure SMTP via WP Mail SMTP or FluentSMTP and ignore the rest.
Gmail
500 emails per day through a free @gmail.com account using SMTP on port 587. Google Workspace accounts get 2,000/day on every paid tier, starting at $7.20/user/month.
Gmail is not a transactional email service. It is a personal mailbox that happens to expose SMTP. There is no API, no delivery analytics, no bounce handling, no webhook notifications. More consequentially: free Gmail accounts DKIM-sign outbound mail under gmail.com, not under the site’s custom domain. WordPress mail routed through a free Gmail account will not pass DKIM alignment for the site’s domain, which means it will not pass DMARC on alignment-mode policies. For a WooCommerce store, a membership site, or anything where deliverability to non-Gmail recipients matters, a provider that signs under the site’s own domain is the right shape: SMTP2GO, Brevo, or Workspace ($7.20/user/month) if Gmail is otherwise the desired path.
The honest use case is the "already have it" one: a low-traffic informational site sending a handful of emails a day, where the operator already has a Google account and does not need custom-domain authentication. Configure with OAuth2 (preferred) or an Less Secure App (LSA) access was Google's name for the third-party authentication path that used a plain account password against Gmail's SMTP, IMAP, and POP endpoints. Google shut it down for consumer accounts on 30 May 2022 and for Workspace accounts on 1 May 2025; OAuth, App Passwords, or a different sending provider replace it. Read full reference → in the mailer plugin, and outbound mail routes through Google. Deliverability to Gmail inboxes is reliably good because Google trusts its own infrastructure. Deliverability elsewhere depends on the site’s volume and reputation, which is the part Gmail does not help with.
Netcore
100 emails per day on the perpetual free tier, with a separate 30-day trial that opens up 30,000 emails from a verified domain for initial evaluation. Netcore (formerly Pepipost) is an enterprise transactional API with a developer-focused interface.
The 100/day allowance is the smallest among the permanent tiers in this list: about 3,000 emails per month. Workable for a personal blog or a low-traffic informational site; tight for anything generating WooCommerce traffic, membership signups, or busy contact forms.
The first paid tier jumps to $25/month for 150,000 emails, which is the largest free-to-paid step in this list and reflects Netcore’s positioning toward high-volume senders. A WordPress site outgrowing the free allowance has a long way to fall before it justifies Netcore’s entry paid plan; SMTP2GO’s $10/10K or Brevo’s $9/5K Starter are better fits for the volume range between "fits in a free tier" and "needs an enterprise contract." Netcore’s free tier reads, accordingly, more as a sampling mechanism than as a production offering. Worth considering only if the site’s volume fits inside 100/day and the operator specifically wants an India- or EU-residency option.
Zoho Mail
Zoho Mail’s free plan covers up to 5 users with one custom domain and 5GB per mailbox. SMTP access is documented (smtp.zoho.com), but Zoho Mail is a mailbox service, not a transactional relay. Sending limits are throttled by the hour at 50-500 emails, dynamic based on sender reputation, recipient engagement, and contact quality (per Zoho’s published rates-and-limits documentation). Hourly enforcement is the only published constraint; no monthly cap is documented.
The hourly throttle is the practical constraint. A flash sale generating 100 WooCommerce confirmations in an hour can hit the cap and queue the rest. Steady, low-volume transactional traffic (a few sends per hour) never sees it.
Worth using as a WordPress sending path only if the site already runs on Zoho for team email and the operator wants WordPress notifications to come from the same address. Chosen on its own merits, providers built for transactional sending (SMTP2GO, Brevo) handle bursty traffic without the throttle and surface bounce webhooks and delivery analytics that Zoho does not.
Adjacent: in-WordPress newsletter sending
MailPoet
5,000 emails per month to up to 500 subscribers on the Starter plan. MailPoet is a WordPress newsletter plugin (Automattic-owned, 500K+ installs) that runs inside the WordPress admin and ships with its own sending infrastructure, the MailPoet Sending Service.
This is not a transactional SMTP relay. The free tier’s allowance applies to MailPoet-managed sends (newsletter campaigns, automated welcome sequences, subscriber-facing content), not to WordPress core notifications, WooCommerce receipts, or contact form confirmations. Sites that want both a free newsletter tool and free transactional email need MailPoet for the former and a separate provider (SMTP2GO, Brevo) for the latter. Messages sent through the MailPoet free tier carry MailPoet branding.
The right option for a WordPress site that wants in-dashboard newsletter functionality at no cost and can tolerate the branding. Not a substitute for any of the permanent transactional tiers above.
Trials and sandboxes
These two providers appear on every "free SMTP" list elsewhere. They are listed here so that the distinction is explicit: neither is a permanent free tier.
SendGrid (60-day trial)
100 emails per day for 60 days after signup. After day 60, the free access ends. The first paid tier is $19.95/month for 50,000 emails (Essentials).
SendGrid is an enterprise email platform owned by Twilio, built for high-volume senders. The 60-day window is enough to evaluate the service and validate a WordPress integration; it is not a tier a site can be configured against and forgotten. The pricing reflects the target market: $19.95/month for 50,000 emails is competitive at scale but expensive for a WordPress site sending 500 emails a month, where SMTP2GO and Brevo cover the same volume at $0 indefinitely.
The reason SendGrid appears on every aggregator’s "free SMTP" list is brand recognition, not free-tier quality. For WordPress sites with sustained $0 needs, SMTP2GO or Brevo are the permanent alternatives.
Postmark (developer sandbox)
100 emails per month on the developer sandbox. Postmark’s documentation is explicit that the sandbox exists for testing, not for production: no overages are allowed, and the account stops sending once the cap is hit until it resets.
100 emails a month is below the threshold for any site in active operation. A single WooCommerce order generates multiple emails (confirmation, shipping notification, optional review request); a contact form on a moderately trafficked page can exceed 100 submissions in a month without effort.
Postmark’s paid tier starts at $15/month for 10,000 emails. For sites where transactional deliverability is a business requirement, Postmark on its paid Basic plan is the right default. The sandbox is a developer convenience, not an entry to running a site for free.
Which to pick
Under 1,000 emails/month, transactional relay only. SMTP2GO. Configure once, no branding, no marketing surface area.
Up to 300/day, transactional and possibly marketing later. Brevo. The 300/day cap is shared between transactional and campaign sends, so plan for that if both are in use.
A handful of emails a day and a Gmail account already exists. Gmail via OAuth2. Suitable only where custom-domain DKIM is not required; Workspace ($7.20/user/month) fixes that constraint.
In-WordPress newsletter tool at no cost. MailPoet. Sends MailPoet-managed campaigns only; pair with a transactional provider for WordPress core mail.
Existing Zoho mailbox, low transactional volume. Zoho Mail, accepting the hourly throttle.
Deliverability matters enough to justify $15/month. Skip the free tiers. Postmark on the paid Basic plan is the right answer for sites where transactional mail arriving is the business requirement.
For everything else: configure SMTP2GO, install WP Mail SMTP or FluentSMTP, and move on to a different problem.