SMTP provider and email API connections in MailFleet

MailFleet stores host, port, encryption (STARTTLS/SSL), and authentication locally on your desktop. Test connectivity before assigning a profile to a campaign.

Use custom SMTP when you already operate sending infrastructure, need a private relay, or must keep traffic inside a VPC. You remain responsible for reputation, authentication (SPF, DKIM, DMARC), and provider acceptable use terms.

Ideal for small teams, internal notices, and low-volume operational mail when Google is already your mail system. Google enforces strict daily limits and security policies — not suited for bulk marketing without proper Workspace configuration.

Authenticate with smtp.gmail.com or your Workspace SMTP relay host. Align SPF and DKIM with Google's documentation for your domain.

Works well for organizations standardized on Microsoft 365 that need campaign or lifecycle mail through familiar infrastructure. Microsoft applies throttling, security defaults, and tenant policies that may restrict bulk sending.

Configure SMTP AUTH only if your tenant admin enables it. Consider dedicated transactional providers when volume or marketing throughput grows.

Yahoo SMTP is appropriate for very small operational volumes — not large marketing campaigns. Yahoo aggressively filters bulk patterns and limits connections from consumer accounts.

Use app-specific passwords where required. For marketing or product email at scale, migrate to a transactional ESP and keep Yahoo for personal or test mail only.

Zoho Mail suits SMB teams that host email with Zoho and want to run permission-based campaigns without adopting a separate ESP immediately. Zoho publishes sending limits and anti-abuse policies you must follow.

Store Zoho SMTP credentials in MailFleet locally and test from your desktop before assigning profiles to client or brand workspaces.

SES SMTP is a strong choice when your stack already lives in AWS, you want regional control, and you are comfortable managing sandbox exit, domain verification, and configuration sets in the AWS console.

MailFleet connects with SES SMTP username and password generated in IAM. Pair with SNS or webhooks for event tracking alongside MailFleet local logs.

The SES API path suits teams that prefer API keys over SMTP sessions, need fine-grained error codes, or orchestrate sends alongside other AWS services. MailFleet stores API credentials locally and routes requests according to your profile configuration.

You still manage verification, suppression, and compliance in AWS. MailFleet is the campaign control plane — SES remains the delivery infrastructure.

SendGrid SMTP works well when your runbooks assume SMTP ports and credentials, or when you are migrating from another SMTP-based stack. SendGrid still expects authenticated domains, clear list practices, and compliance with their acceptable use policy.

MailFleet logs SMTP responses and campaign outcomes locally so you can correlate SendGrid events with desktop reporting.

The SendGrid API profile in MailFleet is suited to product email, newsletters, and multi-brand agencies that already standardize on API keys. You get clearer error objects than raw SMTP text in many cases.

Rotate API keys on your security schedule. Document which key belongs to which client workspace inside MailFleet profile notes.

Mailgun SMTP is a practical choice for developers and marketers already verified in Mailgun who prefer SMTP debugging tools. Mailgun monitors reputation, bounces, and complaints on their side — you still need permission-based lists and honest content.

Assign Mailgun SMTP profiles per client in MailFleet to keep agency sends isolated and exportable from local logs.

Mailgun API profiles shine when you need region-specific endpoints, detailed failure JSON, and alignment with application code that already uses Mailgun SDKs. MailFleet becomes the operator UI while Mailgun handles delivery.

Store private API keys only on secured workstations running MailFleet. Rotate keys when staff or clients offboard.

Postmark emphasizes fast transactional delivery and clear separation between transactional and broadcast streams. SMTP access lets MailFleet operators use familiar port and TLS checks before production sends.

Postmark is not a bulk marketing platform — use broadcast messages only with permission-based lists and within Postmark's guidelines.

The Postmark API path is ideal when you want structured error handling and server-side templates alongside MailFleet's desktop campaign manager. API keys are scoped per server in Postmark — mirror that separation in MailFleet profiles.

Combine Postmark message streams with MailFleet SpamAssassin checks and capacity scoring before scaling volume.

Resend targets modern product teams with simple DNS verification and clean APIs; SMTP support lets you test and send through MailFleet without rewriting operational playbooks that assume SMTP diagnostics.

Resend enforces domain verification and acceptable use like any ESP — permission-based lists remain mandatory.

Resend API profiles in MailFleet suit teams that want fast domain setup and JSON APIs without managing SMTP sockets. Pair with MailFleet webhooks to push campaign events into your internal systems.

Document API keys per environment (staging vs production) in MailFleet profile labels to avoid cross-environment mistakes.

Brevo combines marketing and transactional capabilities under one vendor — SMTP access lets MailFleet operators run campaigns while Brevo handles delivery and compliance tooling on their side.

Follow Brevo's list hygiene and sender verification requirements. MailFleet logs help you catch SMTP authentication and throttling issues early.

Brevo API profiles work well for agencies managing multiple brands on Brevo with separate API keys per client. MailFleet keeps credentials on your desktop while you assign the right profile per campaign.

Integrate Brevo webhooks with MailFleet outbound webhooks for a fuller event picture in your ops stack.