Twilio SendGrid vs SendLayer

Twilio SendGrid 81

Bearer keys with full, restricted or billing access, restricted keys carry per-endpoint scopes, subusers get their own keys, and IP access management limits where keys work (30). A key can hold only mail.send, and read-only scopes exist (18). The API doesn't return third-party content. Inbound Parse posts to your own URL (10). Email Activity keeps 3 or 7 days of message events by plan. We found no audit log of key use (8). Twilio holds SOC 2 Type II and ISO 27001, 27017 and 27018, though it says not every credential covers every product, and runs a HackerOne bug bounty and a disclosure programme. www.twilio.com/.well-known/security.txt returned 404 and sendgrid.com's returned 403 on 17 October. Key scopes, IP access management and certifications are per the 1 October check (15).

SendLayer 38

Plain revocable API keys per domain, several allowed, sent in a header; no scopes, expiry or rotation feature beyond creating and deleting keys (20 of 30). No read-only key or approval step (0 of 20). The API returns event data, not received mail (10 of 15). Email logs kept 3, 15 or 30 days by plan, and no log of API calls was found (8 of 15). No security.txt (404), disclosure policy, bug bounty or certification found (0 of 20). Total 38.

Twilio SendGrid 82

Closed service under Twilio's terms, with MIT SDKs (20). The privacy notice (9 April 2026) and the DPA (9 April 2026) agree, per the 2 October check, not re-read on 17 October. Customer content is deleted 30 days after termination and from backups after 60 days, or one year for SendGrid backups, Email Activity keeps 3 or 7 days of events by plan, and SendGrid tracks opens and clicks with web beacons, which the notice discloses. Account data is kept "as long as needed" with no number (25 of 30). Dated deprecation notices exist but with short notice. The removal of legacy SendGrid IP addresses for the API and SMTP was posted on 19 August 2026 for temporary disablement from 24 August and permanent removal on 31 August, and the Domain Authentication change was announced effective the same day, 3 August. Below the 12 given to Twilio for a seven-day notice (10). Twilio's subprocessor page, updated September 2026, lists AWS for email routing in the USA and EU and AWS and Snowflake for Marketing Campaigns in the USA, and the DPA promises 10 days' notice of a new subprocessor and 30 for an infrastructure provider, per the 1 October check (18).

SendLayer 49

Closed service with terms naming SendLayer, LLC under Florida law (15 of 30). The privacy policy is undated, says data is kept as long as the account is active or as needed, and names no retention periods, DPA or processors; only the pricing page gives log retention per plan (8 of 30). No deprecation policy or dated notices (0). No sub-processors or data locations disclosed (0). Total 23.

Twilio SendGrid 76

SendGrid components (Mail Sending with API v3, SMTP and API v2, Webhooks with Event Webhooks and Parse API, the SendGrid API, Marketing Campaigns, Statistics, Email Activity and more) sit on status.twilio.com (20). The history pages, re-read on 1 November, carry the incident data without a script. From 3 August to 1 November 2026 the incidents on SendGrid were minor, marked no impact or announced maintenance. Block-list suppressions updated late on the API from 31 August to 1 September (minor). Link Branding creation with automatic SSL failed with HTTP 500 on 24 September, 09:22 to 11:26 PDT (minor). A small subset of Event Webhook events was delayed on 24 September, 13:40 to 19:24 PDT (minor). Suppression changes weren't applied from 24 to 29 September, so a very small amount of mail went undelivered and some unsubscribes weren't saved, posted on 15 October with no impact marked. A subset of customers saw email deferrals on 1 and 2 October (no impact). SendGrid users on Azure Marketplace couldn't complete setup or plan changes on 24 October from 09:36 to 15:54 PDT (minor, SendGrid Partners only). The 28 October maintenance that delayed some delivery and account changes was announced on 23 October. We read none of these as an hour of a core API down or wide errors, so minor only (20). Per-endpoint limits come back in X-RateLimit headers, but the docs, last modified 2 July 2026, give no numbers, per the 17 October check (8). 429 with X-RateLimit-Reset, and no backoff or idempotency guidance (8). The Twilio APIs SLA, updated 9 April 2026, names the SendGrid Mail Send API among its Services APIs at 99.95 per cent, or 99.99 per cent with Enterprise Edition or a premium email package, with a 10 per cent service credit, per the 2 October check (10). GA (10).

SendLayer 48

Graded with the hosted lines. A Cronitor status page at status.sendlayer.com with components for the app, SMTP, tracking links, the website and each plan's sending IPs, and a history (15 of 20, see below). The 90 days from 8 August hold 98 automated outage entries, 13 of them on SendLayer Services Health, most on per-plan IP monitors, all marked resolved but with no durations or write-ups, so their size can't be judged (5 of 30). Send limits per minute, hour and day are published per plan, plus recipient and size caps (15). 429 appears in the error code list, with no Retry-After, backoff guidance or idempotency for sends (3 of 15). No SLA found (0). The API is at v1 with no beta label (10). The status page's uptime columns showed no data on 6 November, so the component line takes 15 of 20 rather than 20. Total 48.

Twilio SendGrid 67

Scored on the service, as the rubric asks for closed services. Twilio's changelog carries "Unified Login for SendGrid Marketplace Customers", GA, on 16 October 2026, 16 days before this check, with no SendGrid entry since (30). SendGrid entries in the 90 days from 3 August are the Domain Authentication change of 3 August, the Link Branding change of 27 August and Unified Login on 16 October, three in all (20). A public changelog with SendGrid entries, and support by ticket on paid plans. We couldn't see issue replies (8 of 15). Official SDKs exist in seven languages, but Node and Python last shipped on 19 September 2025, confirmed in their tags on 1 November, and Go on 29 May 2025, per the 17 October check. The OpenAPI specs were regenerated on 28 October 2026 (5 of 15). CI workflows exist in the Node SDK repository (4).

SendLayer 40

The Node and Python SDKs were last released as 1.1.0 on 21 August 2026, 77 days before this check (20). One SDK release in the 90 days and no dated changelog (0 of 20). A closed service with a support form and docs updated through 2026, but no public changelog (5 of 15). Not in the official MCP registry (search for sendlayer returned nothing on 6 November). Official SDKs in five languages (10 of 15). The SDK repositories exist on GitHub under sendlayer; their CI wasn't read (5 of 10). Total 40.

Twilio SendGrid 79

OpenAPI 3.1 specs for the whole v3 API in 46 JSON files at twilio/sendgrid-oai, regenerated on 28 October 2026 and tagged 1.0.0.-rc.14, still a release candidate (25). Twilio's docs-wide llms.txt now has a Twilio SendGrid section linking SendGrid pages as Markdown, and the pages answer at a .md URL as text/markdown (10). The reference describes each endpoint but not when to avoid one (10). Typed from OpenAPI (12). Examples in the reference, and the spec documents an ErrorResponse with field and help on mail/send (12). v3 API and a CHANGELOG in the spec repository. Twilio's changelog can be filtered by product, but SendGrid entries sit under three product names (10).

SendLayer 68

OpenAPI file at developers.sendlayer.com/api-reference/sendlayer.json (version 1.0.1) covering four paths, send, events and webhooks (25). llms.txt and Markdown copies of every developer page (10). Operation summaries say what each call does; nothing says when not to use one, and the hosted MCP server's tool definitions aren't public (10 of 20). Parameters are typed but without enums or limits, and the event filter is a free string (7 of 15). Code samples in five languages and a table of 35 error codes, but the spec documents only 200 responses (11 of 15). Version in the path and in the spec, with no public changelog (5 of 15). Total 68.

Twilio SendGrid 30

No x402, MPP or L402 (0). Plan prices are public, but overage rates per 1,000 aren't (10). A 60-day trial at 100 emails a day with no card (20). Browser signup and sender verification, no autonomous route (0).

SendLayer 20

No x402, MPP or L402 (0). Plan prices are public but only as annual plans, with no per-email overage price; accounts are upgraded automatically at the limit (10 of 20). A free trial of 200 emails is offered through checkout; whether it needs a card couldn't be read, since robots.txt disallows the add-to-cart URLs (10 of 20). A person signs up and authorises a domain in a browser (0). Total 20.