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WelcoYour alerts, by text.

One alert email, one text, on every phone

Duplicate protection means your crew hears about each alarm email once, even when a mail server hands it over twice. Welco keeps track of each email and each phone. A retried copy is caught and set aside before it can become a second text. You don't have to turn anything on.

Stop double alert textsBook a demo

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  • Nothing to turn on
  • One text per email for each phone
  • Caught copies cost no credits

Works by email with

  • Access control
  • Ignition
  • Microsoft 365 / Outlook
  • Nagios

No duplicate texts

Try it: turn it off and on.

2

Without it: one mail retry, two buzzes on the nightstand

1

With it: one email, one text

On. The phone gets 1 text.

With No duplicate texts off, the phone gets 2 texts: Welco: [Residence B] Door forced open, Stair 3 exit at 10:12 PM. Reply STOP to opt out. Welco: [Residence B] Door forced open, Stair 3 exit at 10:12 PM. Reply STOP to opt out. With it on, it gets 1: Welco: [Residence B] Door forced open, Stair 3 exit at 10:12 PM. Reply STOP to opt out.
Animation: No duplicate texts switched off and on. Without it: one mail retry, two buzzes on the nightstand. With it: one email, one text.

What the person on call notices

  • One buzz for each alarm email

    A mail retry at 2 a.m. won't wake anyone a second time for the same alarm.

  • Quiet phones during a storm

    Busy mail servers retry more. In an alarm storm, every phone still gets each email one time.

  • Each person still gets theirs

    The check runs per phone, so everyone on a list of several phones still receives the alert.

  • Copies cost nothing

    A copy that's set aside is never sent, so it never uses a message credit.

How does Welco catch duplicate alert texts?

It works in the background of Welco's alert features. You won't find a setting for it, and there's nothing to adjust.

  1. The email comes in with its Message-ID

    Each email carries a hidden label called the Message-ID. When one shows up without it, Welco adds one, so a later copy still matches.

  2. Welco checks every phone on the rule

    It keeps track of which phones already got a text for that ID. A number entered twice on one rule only counts once.

  3. Only phones that haven't had it get a text

    Phones that already got it are skipped. All of this happens before a single text goes out.

A real example: a residence door alarm sent twice

On a college campus in Nova Scotia, an access control server emailed a door alarm. Its mail relay was slow to answer, so it sent the same email again 40 seconds later.

Alert email from access@campus.example.com, subject “Door Forced Open - Residence B Stair 3”. Welco trims it to one text of 89 characters: “Welco: [Residence B] Door forced open, Stair 3 exit at 10:12 PM. Reply STOP to opt out.”

Text received: Welco: [Residence B] Door forced open, Stair 3 exit at 10:12 PM. Reply STOP to opt out.

Characters209891 credit

Animation: the alert email "Door Forced Open - Residence B Stair 3" is trimmed into one text: "Welco: [Residence B] Door forced open, Stair 3 exit at 10:12 PM. Reply STOP to opt out."

Both copies carried the same Message-ID. Campus security's on-call phone got one text, and Welco set the second copy aside. The door forced alarms page walks through setup for these panels.

Each alarm email becomes one text

Sign up and Welco catches mail retries before they reach your crew.

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

Stop double alert textsBook a demo

Which repeats Welco catches, and which begin upstream

Some repeats are created before the email ever reaches Welco. Each of those copies gets its own Message-ID, so Welco sees them as different emails.

A mail server tries again after a timeout

Same Message-ID?
Yes
What the phone receives
One text

A busy mail system passes along the same email twice

Same Message-ID?
Yes
What the phone receives
One text

The same number is listed twice on one rule

Same Message-ID?
Not needed
What the phone receives
One text

Two Outlook or Exchange forwarding rules send the same alert

Same Message-ID?
No
What the phone receives
Two texts until you delete one rule

A mail group lists your Welco address twice, or includes a group that already has it

Same Message-ID?
No
What the phone receives
Two texts until the group is fixed

The system sends a separate email to each contact

Same Message-ID?
No
What the phone receives
One text for every email it sends

Fixing copies made upstream

If one alarm brings two texts, a few minutes with the email headers usually shows why.

  • Check the headers side by side

    Open the full headers on both copies. If the Message-IDs differ, the extra copy was created before it reached Welco.

  • Leave a single path

    Keep one route from the system to your Welco address, and delete the extra forwarding rule or group.

  • Begin with a clean forward

    Our guide to forwarding Outlook alerts sets up a single, tidy path.

Where duplicate protection pays off

Frequently asked questions

Welco removes duplicates, so why did one alert reach me twice?

The copy was most likely made before the email got to Welco. Two forwarding rules or a nested mail group produce separate emails with different Message-IDs. Compare the headers on both copies, then remove the extra path.

Will duplicate protection block the alert to my backup phone?

No. The check runs per phone. An alert sent to three phones reaches each of them one time. Only a second copy to the same phone is skipped.

Can Welco hold back an alarm that keeps repeating every few minutes?

Not today. Welco removes copies of the same email, but a fresh email about the same alarm becomes a fresh text. Use alert rules to drop repeats your system clearly labels, or set the system to send only once.

What makes a mail server send the same alert email twice?

A mail server tries again when it doesn't get a clear answer in time. A slow relay, a long queue or a dropped connection leaves it unsure the first copy arrived. Both copies keep the same Message-ID, and that's how Welco spots the repeat.

Is there a setting to turn on duplicate protection?

No. It covers every alert email on every account. There's no switch for it because you don't need one.

Does Welco treat a recovery email as a copy of the alarm?

No. A recovery is a separate email with its own Message-ID, so it becomes its own text. If recoveries shouldn't wake anyone, an alert rule can leave them in email.

Hear about each alarm once, on every phone

Mail servers retry. Your crew only needs to hear about the alarm one time.

Stop double alert textsBook a demo

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