Connect SMTP / Bulk Provider Sender

Purpose

SuperSend supports connecting mailboxes via raw SMTP/IMAP, API-based email providers (Mailgun, SendGrid, AWS SES, Azure), and bulk provisioning services (Mailreef, Infraforge, Maildoso). This article covers all of these non-Gmail, non-Outlook connection paths.

Before You Start

Read Senders Overview if this is your first time setting up senders. Connecting a mailbox is step one — you'll still need to attach it to a sender profile before it's usable in a campaign.

Open the Connection Wizard

1. Go to Senders in the left sidebar.
2. Click Add Sender → Email Sender.
3. On the method selection screen, click Connect Your Own Mailboxes.
4. On the provider list, choose your provider.

SMTP/IMAP Providers

These providers use standard IMAP for receiving and SMTP for sending. SuperSend pre-fills the host and port settings for most common providers. You add your credentials and connect.

Supported SMTP/IMAP providers with pre-filled settings:

• Zoho Mail
• Namecheap Private Email
• Hostinger
• Titan Email
• IONOS
• Dreamhost
• AOL

For any of these providers, the steps are:

1. Click the provider from the list.
2. Confirm or adjust the pre-filled SMTP/IMAP host and port settings.
3. Enter:

• Email — the full email address.
• Password — the account password (or app password if required by the provider).
• Send As Name — the display name recipients see.
• Any provider-specific fields (e.g., Zoho requires selecting your region).

4. Click Connect (or equivalent button for that provider).

If your provider isn't listed:

Click the "Don't see yours? Enter SMTP/IMAP manually →" link at the bottom of the provider list. This opens a manual configuration form:

Fill in all fields from your email provider's SMTP/IMAP documentation, then click Connect.

Mission Inbox SMTP

Mission Inbox SMTP mailboxes are a common choice for teams using SuperSend's managed infrastructure. When you select Mission Inbox SMTP from the provider list, the wizard goes directly to the manual SMTP/IMAP configuration step (skipping provider-level setup, since Mission Inbox credentials are provided directly by the service).

Enter the credentials provided in your Mission Inbox dashboard and connect.

API-Based Email Providers

API providers don't use IMAP/SMTP — they send via HTTP API and are typically used for high-volume sending. These senders can send at much higher daily volumes than individual IMAP mailboxes but do not support reply tracking via IMAP.

Supported API providers:

• Mission Inbox OBM API — SuperSend's high-volume sending infrastructure
• Mailgun
• SendGrid
• AWS SES
• Azure Communication Services

For Mailgun and SendGrid:

1. Click the provider from the list.
2. Enter:

• API Key — from your provider's dashboard.
• Send As Email — the email address you're sending from.
• Reply-To Email — where replies should go.
• Track Replies toggle — whether to monitor for replies (depends on provider capabilities).

3. Click Connect.

For AWS SES:

1. Click AWS SES.
2. Enter:

• Access Key ID — from your AWS IAM user.
• Secret Access Key — from your AWS IAM user.
• Region — the AWS region where your SES is configured (e.g., us-east-1).
• Send As Email and Reply-To Email.

3. Click Connect.

For Azure Communication Services:

Similar to AWS — enter your Azure connection string or API credentials, sending domain, and reply-to address.

Note on reply tracking with API providers: Unlike IMAP-based senders, API providers typically can't listen for incoming replies through the same account. If reply tracking is important to your workflow, use a separate inbox for replies or configure your provider's inbound routing to a SuperSend-compatible webhook.

Bulk Provisioning Imports (Mailreef, Infraforge, Maildoso)

If you use a bulk mailbox provisioning service, SuperSend can import all your mailboxes at once instead of connecting them one by one.

Supported provisioning services:

• Mailreef
• Infraforge
• Maildoso

Steps for bulk import:

1. Click the provisioning provider from the list.
2. Enter your API credentials or account login for that service.
3. SuperSend fetches all mailboxes from your provisioning account.
4. Select which mailboxes to import.
5. Click Import.

All selected mailboxes are added to your SuperSend Senders list in one operation. This is significantly faster than connecting each mailbox individually when you're working at scale.

CSV Bulk Import

If you have SMTP/IMAP credentials for multiple mailboxes and don't use a provisioning service, you can upload a CSV:

1. In the Email Sender method selection screen, click Bulk Import via CSV instead of "Connect Your Own Mailboxes."
2. Download the CSV template.
3. Fill in credentials for each mailbox (one row per mailbox): SMTP settings, IMAP settings, email address, password, display name.
4. Upload the completed file.

SuperSend processes each row and attempts to connect each mailbox. Rows that fail appear in a failure report.

After Connecting

Connected mailboxes appear in Senders → Mailboxes. Attach them to a sender profile before use in campaigns:

1. Go to Senders → Sender Profiles tab.
2. Open a profile (or create one).
3. Click Add Mailboxes and select the new mailboxes.

See Create and Use Sender Profiles for full details.

Expected Result

Your mailboxes appear in Senders → Mailboxes with active status and are ready to add to sender profiles.

Troubleshooting

• Issue: SMTP connection test fails.

Fix: Double-check host, port, username/password, and TLS settings. Most connection failures are a wrong port (e.g., using 465 instead of 587) or SMTP auth disabled on the provider account.

• Issue: Connected but emails aren't delivering.

Fix: Check that the sending domain has valid SPF/DKIM records. Also confirm the mailbox isn't hitting provider-level daily send limits.

• Issue: API sender connects but replies don't appear in SuperSend.

Fix: API senders don't support IMAP reply monitoring. Configure your provider's inbound email routing, or use a separate IMAP mailbox as the reply-to address.

Related Articles

• Senders Overview
• Connect Gmail/Google Workspace Sender
• Create and Use Sender Profiles

Updated on: 17/03/2026