Email provider migration guides

Compare source message formats, supported features and a controlled cutover to Sendar. SMTP-only apps need an HTTP adapter.

Sending transport

HTTPS REST API. No customer SMTP relay endpoint is documented. SMTP-only applications need an HTTP adapter or should keep their current relay.

Recipients and headers

The send contract accepts a to array (up to 50 recipients). CC, BCC, Reply-To, arbitrary headers and provider tags are not supported by this contract. Do not silently discard them.

Templates

Create new Sendar templates and map templateId and variables. Variables are strings and missing or unknown keys fail validation. Existing provider template IDs and template engines are not portable.

Attachments

Single sends accept up to five base64 files, with 1.3 MB total decoded content. Use filename, content and optional contentType. URL attachments, inline CID and raw MIME are not supported by this contract.

Events

Sendar exposes sent, failed, scheduled, canceled, bounced, complained, opened and clicked events. There is no per-message delivered webhook. Sent means provider acceptance, not inbox placement.

Scheduling and batches

Scheduling is up to 30 days ahead on Growth and above. Batch sends accept up to 100 messages and do not support attachments or scheduling. Quotas count recipients.

Suppression and retries

Preserve opt-outs, complaints and permanent bounces in your application before cutover. Reconcile both providers during rollback. Do not assume provider suppression lists or idempotency keys transfer.

Migrate from Resend to Sendar

Map your Resend transactional email workflow, check compatibility and plan a reversible move to Sendar.

Migrate from SendGrid to Sendar

Map your SendGrid transactional email workflow, check compatibility and plan a reversible move to Sendar.

Migrate from Postmark to Sendar

Map your Postmark transactional email workflow, check compatibility and plan a reversible move to Sendar.

Migrate from Amazon SES to Sendar

Map your Amazon SES transactional email workflow, check compatibility and plan a reversible move to Sendar.

Migrate from Mailgun to Sendar

Map your Mailgun transactional email workflow, check compatibility and plan a reversible move to Sendar.

Migrate from Brevo to Sendar

Map your Brevo transactional email workflow, check compatibility and plan a reversible move to Sendar.

Migrate from Mailjet to Sendar

Map your Mailjet transactional email workflow, check compatibility and plan a reversible move to Sendar.

Migrate from SparkPost to Sendar

Map your SparkPost transactional email workflow, check compatibility and plan a reversible move to Sendar.

Migrate from SMTP2GO to Sendar

Map your SMTP2GO transactional email workflow, check compatibility and plan a reversible move to Sendar.

Migrate from SMTP.com to Sendar

Map your SMTP.com transactional email workflow, check compatibility and plan a reversible move to Sendar.

Migrate from Elastic Email to Sendar

Map your Elastic Email transactional email workflow, check compatibility and plan a reversible move to Sendar.

Migrate from Zoho ZeptoMail to Sendar

Map your Zoho ZeptoMail transactional email workflow, check compatibility and plan a reversible move to Sendar.

Migrate from Mailchimp Transactional (Mandrill) to Sendar

Map your Mailchimp Transactional (Mandrill) transactional email workflow, check compatibility and plan a reversible move to Sendar.

Migrate from Mailtrap Email Sending to Sendar

Map your Mailtrap Email Sending transactional email workflow, check compatibility and plan a reversible move to Sendar.