Send one message on every channel with guaranteed delivery

Reach a user by email and SMS from a single call, either on both channels at once or in a priority order where Multisend moves to the next channel when a delivery fails.

Read documentationView pricing

Fall back from email to SMS in the same call

Multisend sends one message on every channel in the call at once, or it tries the channels one at a time in your priority order until a delivery succeeds. You make the same call for both modes, with or without a priority list.

How Multisend picks a channel and falls back

Simultaneous broadcast

In broadcast mode, Multisend sends on email and SMS at the same time from a single API call. Multisend sends each channel the content that you write for it.

Priority-based fallback

Set the order in which Multisend tries your channels. Multisend sends on the first channel and moves to the next one only when the first one fails.

Conditional routing

Choose the delivery events that trigger a fallback. Multisend can switch to SMS when an email bounces, or when the recipient does not open the email within a delay that you set.

Channel-specific content

Give each channel its own template. The email can use your full HTML layout, while the SMS contains a 160-character version of the same notification.

Cascade tracking

Multisend records every send in a cascade, such as an email that bounces and then an SMS that the carrier delivers. Each recipient has a single timeline that shows the whole sequence.

Unified analytics

Compare delivery, open, and reply rates for each channel in one dashboard. For appointment reminders, for example, you can see whether more recipients confirm by SMS or by email.

99.99%
Message reach rate

Messages delivered on at least one channel in the cascade

Email and SMS
Channels in one call

Tried in the order that you set

< 30s
Fallback trigger

From failure detection to the next channel

Build faster with solutions designed for real-world needs

Send a password reset by email first and by SMS if the email fails

Set a cascade with email first and SMS second. When the email bounces or fails, Multisend sends the SMS within 30 seconds after it detects the failure. Multisend then reports the message as delivered on whichever channel succeeds.

Impact

The sample sends Sigrid Kallio a Quintwood Pharmacy reset link by email. If that email fails, Multisend texts a reset code to Sigrid's phone. The link and the code each expire 10 minutes after Multisend sends them.

Prompt for a coding agent: Send the password reset by email, and text a reset code when the email fails.

Conjoin IDE

Select a file to view its contents

Escalate reminders by time and engagement

Set escalation rules on time and engagement. For an appointment, Multisend can send an email 24 hours ahead and switch to SMS 4 hours ahead if the email is still unopened. Multisend can then send a last SMS 30 minutes before the appointment when the patient does not confirm by then.

Impact

The sample schedules the reminder for Lina Park at 13:30 UTC on May 13, 2026, which is 24 hours before Lina's 9:30 AM Eastern appointment on May 14. In the priority list, email comes first and SMS second. Because the sample sets accepts_replies on both messages, Lina can reply CONFIRM on either channel.

Prompt for a coding agent: Remind patients a day before their appointment by email, then SMS, and let them reply CONFIRM.

Conjoin IDE

Select a file to view its contents

Text a customer only when they miss the order email

With email first in the priority order, Multisend sends the SMS only when the email bounces or the recipient leaves it unopened for 48 hours. Conjoin then bills you for SMS only on the orders where Multisend falls back.

Impact

The sample sends the Akpe Hardware order confirmation for Sahil Verma by email, with an SMS version that Multisend sends only if the email fails.

Prompt for a coding agent: Email the order confirmation, and text the customer when the email fails.

Conjoin IDE

Select a file to view its contents

Send the email and the SMS at once, each with its own content

When the call has no priority list, Multisend sends on every channel in it at the same time. The email contains the full HTML version, while the SMS contains a short version of the same notice.

Impact

The sample sends a doors-open notice for Hall A to two Larksong Tickets customers by email and to two phone numbers by SMS in one call.

Prompt for a coding agent: Send the doors-open notice by email and SMS at once, with different content on each.

Conjoin IDE

Select a file to view its contents

Build your next app on Conjoin

Conjoin will open with a free Build tier, while the pricing page already lists the launch prices for Pro and Business. If you tell us what you're building, we'll talk you through early access.

See pricingGet early access