The engine that delivers your emails
Connect the software you already use to our sending servers: from then on your emails leave from addresses that the major providers know and trust. You change nothing, only the route changes.
Try it free for 14 days, €0 today. Then from €12.90/month + VAT for 10,000 emails on the annual plan. Servers and data in the European Union.
Preview: Order #2841 confirmed, from Your store. Thanks, your order is being prepared.
Who uses it
Online store, website, office, custom software: if it sends email, it can send it from here.
Trademarks belong to their respective owners.
E-commerce
Order confirmations, shipping and returns from your online store: these are the emails your customer is waiting for, and they are the ones that cannot end up in spam.
Website or Blog
Contact forms, sign-ups, password resets: they leave from our servers instead of your hosting’s, which is often already flagged.
Email Mailbox
An office’s service emails can go through here too, without weighing down the company mailbox and without the provider’s daily limits.
Application
Custom software sends its emails with four configuration settings, or with a single call if you prefer the API.
It sits in the middle, and nobody sees it
You don’t need to change software or learn anything new. Your management system keeps doing what it did: only the route your emails take to go out changes. From there on SMTP Senpai delivers them, from addresses that the major providers know and trust.
Not just newsletters: the emails that have to arrive
They are the ones your system already sends every day and your customer is waiting for. If one of them ends up in spam, you don’t lose a campaign: you lose an order, a payment or an appointment.
Order and shipping confirmations
Your store sends the confirmation, tracking and returns. These are the emails your customer really waits for: if they end up in spam, the phone starts ringing.
Invoices and reminders
Your management system attaches the invoice and reminds about due dates. There’s no room for mistakes here: every undelivered email is a payment that slips.
Passwords and logins
Password reset, address verification, second factor. They need to arrive within seconds.
Bookings and reminders
Medical practices, restaurants, gyms, workshops: appointment confirmation and a reminder the day before. Fewer empty slots, fewer phone calls.
Quotes and negotiations
Your CRM sends the quote and the automatic replies. Knowing whether it was delivered changes how you follow up with the customer.
Tickets and support
Opened tickets, replies, expiry notices: service messages that must get through even when volume rises.
Alerts from your software
Nightly reports, alarms, processing results. Not much per day, but if it doesn’t arrive you find out too late.
Newsletters made elsewhere
Already have a newsletter tool and only need the part that delivers? SMTP Senpai does that, and only that.
Sending on behalf of your clients
You’re an agency or a software house: you send on behalf of others, with different domains, and want a single place to keep it all under control.
Three ways, pick yours
They all lead to the same place and take a few minutes. No technician needed, unless you want the third one.
From the software you already use
In your management system, website or invoicing software there’s a screen asking for «SMTP server, port, username, password». Copy the four details from your area and you’re done.
Server=relay.mailsenpai.com Port=2525 Security=STARTTLS Username=from your area Test email delivered
From your WordPress site
Install a free mail plugin, paste the same four details and from then on orders, contact forms and password resets leave from our servers.
# WordPress mail plugin Mailer=Other SMTP Host=relay.mailsenpai.com Port=2525 Orders and forms send from here
From your applications, via API
If you have a developer or custom software, a single call sends the email and replies with the result. With the same key you read statistics and manage the addresses not to contact.
curl -X POST https://app.mailsenpai.com/relay/v1/invio \ -H "Authorization: Bearer msp_…" -d @email.json Email sent: the result is in the log
Four details, and you’re done
As soon as the service is active you find everything on a single page: server, port, username and password. Copy them with one click and paste them where your software asks for them.
- Test it right away. One button sends a verification email with your credentials: if it arrives, the connection works.
- You always know what’s left. The month’s volume is right at the top, no searching.
- Change password whenever you like. The old one stops working instantly.
- Ready-made examples. PHP, WordPress, API and command line, with your details already filled in.
The numbers, in plain English
It’s not a black box. Every month we tell you how it went compared with before, with the numbers that matter and no acronyms to decode: how many were sent, how many arrived, how many bounced and why.
- We do the comparison. Month, quarter, year: always over the same number of days, otherwise it means nothing.
- A sentence that explains. «Month improving», «watch the bounces»: first the numbers, then what they mean.
- What you should do. If four addresses have been bouncing for three weeks we tell you, and we tell you to remove them.
- Pages stay light. We keep daily totals, not millions of rows: it opens in a flash even after years.
We remove the bounces for you
Continuing to write to addresses that bounce or that reported you as spam is the fastest way to ruin your deliverability. We notice it first: those addresses go into a list automatically and emails to them are no longer sent — and they don’t use up your volume.
- It happens on its own. Hard bounces and spam complaints enter the list without you having to do anything.
- You always see why. Next to each address there’s the reason and the date.
- If it’s a mistake, tell us. Ask for the unblock and we check it: that way nobody removes a block that’s needed on their own.
- Details when you want them. The delivery-by-delivery log is there, but stays closed until you need it.
Your website form too, without writing code
If you have a website that can’t send email — a static page, a theme without plugins, a hosting that blocks mail — SMTP Senpai gives you an address to put in your form. From then on every submission reaches you by email, already formatted, with the «reply» button writing to whoever contacted you.
<form action="https://app.mailsenpai.com/relay/f/…" method="POST"> <input name="name"> <input name="email"> <textarea name="message"></textarea> </form>
<form action="https://app.mailsenpai.com/relay/f/…" method="POST"> <input name="name"> <input name="email"> <textarea name="message"></textarea> </form>
- No bots. An invisible honeypot field discards automated submissions without bothering people who really write.
- Automatic confirmation. If you want, whoever writes to you instantly receives a reply in your own words.
- Everything archived. Every submission stays available and can be downloaded as a spreadsheet.
- Only from your sites. You can say which domains the form is accepted from: nobody else can use it.
SMTP Senpai facts, all in one place
What you need to choose an SMTP service: what it costs, where the data lives, how to connect it and what happens when something goes wrong.
- SMTP connection. Server relay.mailsenpai.com, port 2525 with STARTTLS, personal username and password.
- REST API. With a key you send emails, read results and statistics and manage the do-not-contact list. Read the API documentation
- Website forms. An address to put in your form’s “action”, even on a static site: every submission reaches you by email.
- Your domain. DKIM signing on your domain: we give you the SPF, DKIM and DMARC records to publish and we check them.
- No suspension for a threshold. If you cross a bounce or complaint threshold we don’t block you: we alert you and tell you what to fix.
- Volume under control. Alerts at 50, 80 and 100%; dedicated IP from €15/month, included from 150,000 emails a month.
- People, not just tickets. Support from real people, clear invoicing and prices in euro.
Got a specific case? Start here
You choose the volume, no surprises
You can start on shared addresses, already warmed up and with a reputation built over the years, or have an IP address all your own: in that case we bring it up to speed a little at a time, because a new reputation can’t be bought, it has to be built.
Choose how many emails a month you need, from 10,000 up. We alert you at 50, 80 and 100% of your volume: if you need more in a given month, you decide whether to stop or keep sending in blocks of 1,000, up to a spending cap you set. And if something doesn’t arrive, your area tells you why.
The speed is ours. The result is yours.
Behind every send there are our own servers, kept in order by people who do only this: queues that empty quickly, automatic retries when a provider slows down, signatures and reputation kept under control. You see the result: how many emails were delivered and, for the others, the reason.
From trial to first send, in four steps
You usually go live the same day. Your part takes five minutes.
- 1Step 1
Start the trial
From the checkout, in a few minutes: 14 days free, €0 today. Pick your plan volume from 10,000 emails a month; if you're not sure, we'll look at it together.
- 2Step 2
We verify the domain
Three DNS records on your domain are needed: they tell providers those emails are really yours. We give them to you and we check them.
- 3Step 3
Copy four details
Server, port, username and password appear in your area. Paste them where your software asks for them: nothing else changes.
- 4Step 4
Send the test
A button in the panel sends a verification email. If it arrives, you're done: from then on you control everything from the same page.
If you’re coming from another service you don’t need to stop anything: it runs alongside your current sending, traffic is moved a little at a time and we check together how it’s going. The switch is invisible from the outside.
Reviews
What our customers say
4.7/5
across 83 public reviews
“…semplice da usare, funzionalità innovative e complete e sopratutto il servizio clienti e il coach dedicato!”
Our translation from Italian: “Easy to use, innovative and complete features and, above all, the customer service and the dedicated coach!”
Read on Trustpilot
“…Le automazioni e le statistiche dettagliate mi aiutano a risparmiare tempo e migliorare i risultati.”
Our translation from Italian: “The automations and detailed statistics help me save time and improve my results.”
Read on Trustpilot
“MailSenpai é una delle poche aziende che ti consente di inviare enormi volumi di mail e di creare dei trigger che facilitano le automazioni complesse di qualsiasi e-commerce.”
Our translation from Italian: “MailSenpai is one of the few companies that lets you send huge volumes of email and create triggers that make complex automations easier for any e-commerce business.”
Capterra · August 2025
Read on Capterra
“…sono stato guidato scrupolosamente in tutti i passaggi, dall’acquisto, alla programmazione, sono davvero dei professionisti del settore.”
Our translation from Italian: “I was carefully guided through every step, from purchase to scheduling: they are true professionals in the field.”
Read on Trustpilot
“Sono ormai 4 anni che utilizziamo questa piattaforma per l’invio delle nostre Newsletter…”
Our translation from Italian: “We have been using this platform to send our newsletters for 4 years now.”
Read on Trustpilot
“Ottimo prodotto e ottima assistenza da parte del personale tecnico, disponibile, molto competente e prepararato”
Our translation from Italian: “Excellent product and excellent support from the technical staff: helpful, very competent and well prepared.”
Capterra · January 2025
Read on Capterra
“Ottima, è il partner ideale per le campagne DEM”
Our translation from Italian: “Excellent, it is the ideal partner for email marketing (DEM) campaigns.”
Capterra · January 2024
Read on Capterra
“…I had a question pop up and their team was easy to reach and responsive to my questions.”
G2 · August 2023
Read on G2
“Grazie a mailsenpai la mia azienda è riuscito ad aumentare il fatturato dall’attività di email marketing grazie a tassi di aperture delle mail molto elevati.”
Our translation from Italian: “Thanks to mailsenpai my company increased the revenue from its email marketing activity, thanks to very high email open rates.”
Capterra · April 2023
Read on Capterra
“…la piattaforma è rapida e intuitiva e i gestori sono molto disponibili per qualsiasi necessità”
Our translation from Italian: “The platform is fast and intuitive, and the people who run it are very helpful with any need.”
Capterra · December 2022
Read on Capterra
“Sono rimasto colpito positivamente dal team telefonico per le loro precise delucidazioni sul servizio in base all’utilizzo personale aziendale.”
Our translation from Italian: “I was positively impressed by the phone team for their precise explanations of the service, based on our own business use.”
Capterra · December 2021
Read on Capterra
“…Everything works smooth and if we have a question, they are very fast in responding and finding solutions!”
Capterra · October 2021
Read on Capterra
Reviews are quoted word for word from the portals shown, with date and link to the source; “…” marks an excerpt. Reviews written in Italian are shown in the original, followed by our translation. Capterra reviews also appear on GetApp and Software Advice (same network, not additional reviews). Capterra reviews constitute the subjective opinions of individual end users based on their own experiences and do not represent the views of Capterra or its affiliates.
FAQ
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