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WelcoYour alerts, by text.

Secure email to SMS that only your approved systems can use

Secure email to SMS keeps your Welco address locked to the alarm systems you name, so the on-call cellphone only buzzes for real trouble. Mail from anyone else bounces. A spammer, a stranger or the scanner on the second floor can't reach your crew. You approve each system's From address one time.

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  • Approve each system one time
  • Mail from strangers bounces
  • Refused mail costs no credits

Works by email with

  • Nagios
  • Microsoft 365 / Outlook
  • Google Workspace Groups
  • Data loggers

Approved senders only

Try it: turn it off and on.

3

An open address: anything that lands there becomes a text

1

Approved senders only: your alarm systems, nothing else

On. The phone gets 1 text.

With Approved senders only off, the phone gets 3 texts: Welco: [Mill 1] Air compressor 2 high discharge pressure at 2:40 AM. Reply STOP to opt out. Welco: Scanner-2F document scanned, 3 pages. Reply STOP to opt out. Welco: Your parcel is waiting, confirm delivery here. Reply STOP to opt out. With it on, it gets 1: Welco: [Mill 1] Air compressor 2 high discharge pressure at 2:40 AM. Reply STOP to opt out.
Animation: Approved senders only switched off and on. An open address: anything that lands there becomes a text. Approved senders only: your alarm systems, nothing else.

What approved senders do for the person on call

  • No stranger can text your crew

    Alert addresses get shared and guessed. Email from a sender you haven't approved is never turned into a text.

  • Office mail stays in the office

    Scan-to-email printers, newsletters and junk mail are turned away first, before a single rule looks at them.

  • One runaway system can't empty the plan

    Give each sender a daily or monthly cap, so a server stuck in a loop can't use up your message credits.

  • Each refusal comes with a reason

    The feed shows who sent it and why it was refused, for example Blocked: sender not in allowlist.

How Welco screens every alert email

The sender check comes first, ahead of every other Welco feature. This is what happens to each message sent to your address.

  • Accepted or bounced

    Every system mails from a From address, such as bms@mill.example.com. Approved addresses can become texts. Anything else is bounced.

  • Sender checks on record

    Welco logs the SPF, DKIM and DMARC result for each email. Those results show whether the message truly came from the domain it claims.

  • A cap for each sender

    A daily or monthly limit on one sender stops a stuck alarm loop from burning a month of credits overnight.

  • All senders on one bill

    Every approved sender bills to the account owner's plan, no matter how many systems you connect.

Approve a new sender in 3 steps

Plan on a few minutes for each system. You don't change anything on the system itself.

  1. Look up the system's From address

    Open a recent alert email or check the system's mail settings. You'll often see something like alarms@, noreply@ or bms@ at your own domain.

  2. Add it to your approved senders

    Add that address in Welco. If alerts reach you through a forwarding mailbox or a Google Group, approve the forwarding address, because that's what Welco receives.

  3. Run a test alarm

    Fire a test from the system and check that the feed lists it as accepted. Turn on test mode first if no real text should go out yet.

Keep your alert address for your own systems

Sign up, verify your business with your EIN or Canadian Business Number, and approve the systems allowed to text your team.

7-day free trial, 15 message creditsCard required for verificationNo charge for 7 daysEmail reminder before billing

Approve my alarm systemsBook a demo

A real example: one alarm accepted, two strangers refused

At a sawmill in northern BC, a PLC gateway emails a compressor alarm. Its address is approved, so the on-call millwright gets a text.

Alert email from plc-gateway@mill1.example.com, subject “ALARM Air Compressor 2”. Welco trims it to one text of 93 characters: “Welco: [Mill 1] Air compressor 2 high discharge pressure at 2:40 AM. Reply STOP to opt out.”

Text received: Welco: [Mill 1] Air compressor 2 high discharge pressure at 2:40 AM. Reply STOP to opt out.

Characters199931 credit

Animation: the alert email "ALARM Air Compressor 2" is trimmed into one text: "Welco: [Mill 1] Air compressor 2 high discharge pressure at 2:40 AM. Reply STOP to opt out."

When a scanner's email and a phishing message hit the same Welco address, both bounce. Neither one reaches a phone or uses a message credit. For the crew, a number used only for your alerts makes a real alarm easy to recognize.

Setups where the approved address takes a second look

Most systems mail from one fixed address. These four common setups need a bit more care.

Frequently asked questions

What happens on the sender's side when Welco refuses an email?

The sending mail server gets a bounce that says the message wasn't accepted. Nothing is texted and no credit is used. The Welco feed logs the email and the reason, so you can approve it if it turns out to be yours.

Could someone forge the address of a sender we approved?

Anyone can forge a From line on an email. That's why Welco logs SPF, DKIM and DMARC results, which show whether the mail really came from that domain. Treat your Welco address like an unlisted phone number and keep it private.

Does Welco connect into our network or our mail server?

No. Your system mails its alert out, just as it emails anyone else, and Welco only receives it. You install no agent, open no inbound port and share no mail login. Sender approval is done inside Welco.

Do I have to approve every monitoring server one by one?

You approve sending addresses, not servers. If a dozen servers mail through one alerts mailbox, approving that address covers all of them. If each server mails from its own address, approve each address.

Our alerts pass through Outlook or a Google Group first. Which address gets approved?

The one the forwarded mail arrives from, since that's the address Welco sees. The guides to Microsoft 365 forwarding and Google Groups alerts show where to find it.

Our logger vendor emails alerts for many companies from one address. Could another customer text us?

No. Welco tells accounts apart by the Welco address each email was sent to. A refused attempt gets a neutral bounce that doesn't reveal whether an account exists, and the account owner hears about it separately.

Let only your own systems reach the on-call phone

Approve your alarm senders one time, and everything else gets bounced.

Approve my alarm systemsBook a demo

7-day free trial, 15 message creditsCard required for verificationNo charge for 7 daysEmail reminder before billing