Send email in Ruby via HTTP API (send and receive)
Send email from Ruby with one HTTP call — no ActionMailer, no SMTP. The send code with Net::HTTP, how to receive the reply, and error handling.
Sending email from Ruby usually means ActionMailer plus SMTP settings to maintain. A free HTTP email API replaces that with one Net::HTTP call — no SMTP config — and it can read the reply, which ActionMailer can’t.
Send email in Ruby
A small helper around Net::HTTP keeps it tidy and raises on errors:
require "net/http"
require "json"
BASE = "https://login.ollastack.com"
TOKEN = "fmd_…"
def call(method, path, body = nil)
uri = URI("#{BASE}#{path}")
req = (method == :post ? Net::HTTP::Post : Net::HTTP::Get).new(uri)
req["Authorization"] = "Bearer #{TOKEN}"
req["Content-Type"] = "application/json"
req.body = body.to_json if body
res = Net::HTTP.start(uri.host, uri.port, use_ssl: true) { |h| h.request(req) }
raise "Request failed (#{res.code}): #{res.body}" if res.code.to_i >= 400
JSON.parse(res.body)
end
# create a mailbox once
mbx = call(:post, "/api/mailboxes",
{ name: "ruby", mode: "agent", handle: "ruby" })
# send
call(:post, "/api/mailboxes/#{mbx['id']}/send",
{ to: "user@example.com", subject: "Hi", text: "Sent from Ruby." })
No SMTP host, no port, no ActionMailer setup — one HTTPS request that returns a msg_… id.
Receive the reply
The same helper long-polls for the next inbound message:
msg = call(:get, "/api/mailboxes/#{mbx['id']}/wait?timeout=60")
puts msg["subject"], msg["codes"].inspect # OTP already extracted
That’s the half ActionMailer can’t do — read inbound mail and pull the code without parsing it yourself.
Send HTML, not just text
Swap text for html (or send both — text is the fallback for clients that don’t render HTML):
call(:post, "/api/mailboxes/#{mbx['id']}/send", {
to: "user@example.com",
subject: "Welcome",
html: "<h1>Welcome</h1><p>Thanks for signing up.</p>",
text: "Welcome — thanks for signing up.",
})
The same endpoint takes both; add a reply_to to route replies to a specific address.
Why an API beats ActionMailer / SMTP
ActionMailer ties you to SMTP settings and only sends. The API sends from an authenticated domain, returns a structured error, and also receives — ideal for OTP testing in CI or giving an agent an inbox from a Rails job.
Error handling
The helper raises on any >= 400; on 429 sleep briefly and retry. Read the JSON error body for the code and message instead of assuming success.
See the email API overview, the PHP version, and test OTP email in CI.
Get a free token — send and receive from Ruby, no card.
Frequently asked questions
How do I send email in Ruby without SMTP?
POST to the send endpoint with Net::HTTP: a JSON body (to, subject, text) and a Bearer token. No SMTP host or ActionMailer config — one HTTPS request that returns a message id.
Can Ruby receive email too?
Yes. GET the wait endpoint with the same token to long-poll for the next inbound message, then parse the subject, body, and extracted codes/links. SMTP libraries only send; this also receives.
Does it work with Rails?
Yes — it's a plain HTTP call, so use it from a service object or job instead of ActionMailer when you need receiving, OTP testing, or agent mail.
Is it free?
The free tier sends and receives with no credit card.
Last updated June 21, 2026. Spotted something out of date? Email hello@ollastack.com.