Developer-focused transactional and marketing email delivery via API and SMTP
Postmarkapp (postmarkapp.com): Developer-focused transactional and marketing email delivery via API and SMTP. Category on TopCheckouts: Developer tools.
In September 2026, Similarweb estimates about 10,969 visits went from Postmarkapp to a checkout payment page — #318 of the 607 sites we track. That is 125% up from the April–June monthly average of 4,872.
Total website visits that month were about 211,195 (Similarweb 3-month total, split by Semrush monthly trend). Roughly 5.2 of every 100 visits reached the checkout page.
Largest September traffic sources: direct 84%, search 16%, AI assistants 0%. (Source breakdown from Semrush, desktop only.)
New-user source is unclear: mostly direct visits (about 84%) with no visible invite or sharing mechanics, so new users likely come from word of mouth, private channels or off-site communities.
Pricing: $15/mo (10,000 emails).
Semrush source breakdown (desktop)
In September 2026, Similarweb estimates about 10,969 visits went from Postmarkapp to a checkout payment page — #318 of the 607 sites we track. That is 125% up from the April–June monthly average of 4,872.
New-user source is unclear: mostly direct visits (about 84%) with no visible invite or sharing mechanics, so new users likely come from word of mouth, private channels or off-site communities.
Pricing: $15/mo (10,000 emails).
Checkout visits are Similarweb's estimate of visits from this site to a checkout payment page; opening checkout is not paying, so this is not revenue. See the methodology for how website visits and source mix are computed. Updated 2026-10-21.