Email Deliverability Guide

Comprehensive guide to email deliverability and SMTP configuration for Buzzy apps

When setting up email for your Buzzy app, proper configuration is crucial to ensure your emails reach recipients' inboxes rather than being filtered as spam. This guide provides detailed configuration instructions for popular email providers and essential anti-spam best practices.

Overview

Email deliverability depends on several factors:

• SMTP Configuration: Proper server settings and authentication

• Domain Authentication: SPF, DKIM, and DMARC records

• Sender Reputation: Consistent sending practices and monitoring

• Content Quality: Professional email content and formatting

Generic Anti-Spam Best Practices

SPF (Sender Policy Framework)

SPF prevents email spoofing by specifying which servers can send email for your domain.

Action: Add a TXT record to your domain's DNS:

v=spf1 include:[your-provider-spf] -all

Replace [your-provider-spf] with your email provider's SPF record (see provider sections below).

DKIM (DomainKeys Identified Mail)

DKIM digitally signs your emails to prove authenticity and prevent tampering.

Action:

1. Enable DKIM in your email provider's settings

2. Add the provided CNAME records to your domain's DNS

3. Verify DKIM is active before sending production emails

DMARC (Domain-based Message Authentication, Reporting, and Conformance)

DMARC tells receiving servers what to do when SPF or DKIM fails and provides reporting.

Action: Add a TXT record to your domain's DNS:

_dmarc.yourdomain.com  IN  TXT  "v=DMARC1; p=quarantine; rua=mailto:[email protected]"

Policy Options:

• p=none: Monitor only (recommended for testing)

• p=quarantine: Send suspicious emails to spam folder

• p=reject: Reject emails that fail authentication (strictest)

General Best Practices

• Use a real "From" address: Avoid generic addresses like noreply@

• Maintain consistent sending patterns: Avoid sudden volume spikes

• Monitor bounce rates: Keep bounce rates below 5%

• Use professional email content: Avoid spam trigger words and excessive formatting

• Implement proper unsubscribe mechanisms: Honor unsubscribe requests promptly

Provider-Specific Configurations

Microsoft Office 365

Recommended for: Organizations already using Microsoft 365 for email

SMTP Settings

Setting	Value
SMTP server	smtp.office365.com
SMTP port	587 (STARTTLS)
Encryption	STARTTLS (sometimes called "TLS")
Authentication	Username + Password (user's O365 email and password or App Password if MFA enabled)
Username	[email protected]
Password	O365 password (or App Password)

SMTP URL Format: smtps://[email protected]:[email protected]:587

Note: Microsoft requires SMTP AUTH to be enabled for the mailbox. Reference

Domain Authentication Setup

SPF Record:

v=spf1 include:spf.protection.outlook.com -all

DKIM Setup:

1. Go to Microsoft 365 Defender portal

2. Follow Microsoft's DKIM instructions

3. Add the two CNAME records shown in the portal to your DNS

DMARC Record:

_dmarc.yourdomain.com  IN  TXT  "v=DMARC1; p=quarantine; rua=mailto:[email protected]"

Office 365 Specific Notes

• Sending Limits: Check Microsoft 365 sending limits

• Message Trace: Use Microsoft 365 Message Trace to monitor email delivery

• MFA Considerations: If Multi-Factor Authentication is enabled, use App Passwords instead of regular passwords

SendGrid

Recommended for: High-volume transactional emails and advanced analytics

SMTP Settings

Setting	Value
SMTP server	smtp.sendgrid.net
SMTP port	587 (STARTTLS) or 465 (SSL)
Encryption	STARTTLS or SSL
Authentication	Username + API Key
Username	apikey
Password	Your SendGrid API Key

SMTP URL Format: smtps://apikey:[email protected]:587

Domain Authentication Setup

SPF Record:

v=spf1 include:sendgrid.net -all

DKIM Setup:

1. In SendGrid dashboard, go to Settings > Sender Authentication

2. Authenticate your domain

3. Add the provided CNAME records to your DNS

DMARC Record:

_dmarc.yourdomain.com  IN  TXT  "v=DMARC1; p=quarantine; rua=mailto:[email protected]"

SendGrid Specific Notes

• API Key Security: Use API keys with minimal required permissions

• Dedicated IP: Consider dedicated IP for high-volume sending

• Suppression Management: SendGrid automatically manages bounces and unsubscribes

Mailgun

Recommended for: Developers who need programmatic email control and detailed APIs

SMTP Settings

Setting	Value
SMTP server	smtp.mailgun.org
SMTP port	587 (STARTTLS) or 465 (SSL)
Encryption	STARTTLS or SSL
Authentication	Username + Password
Username	[email protected]
Password	Your Mailgun SMTP password

SMTP URL Format: smtps://[email protected]:[email protected]:587

Domain Authentication Setup

SPF Record:

v=spf1 include:mailgun.org -all

DKIM Setup:

1. In Mailgun dashboard, go to Sending > Domains

2. Add your domain and verify ownership

3. Add the provided TXT records to your DNS

DMARC Record:

_dmarc.yourdomain.com  IN  TXT  "v=DMARC1; p=quarantine; rua=mailto:[email protected]"

Mailgun Specific Notes

• Domain Verification: Verify domain ownership before sending

• EU Region: Use smtp.eu.mailgun.org for EU region

• Webhook Integration: Set up webhooks for delivery tracking

Amazon SES

Recommended for: AWS-integrated applications and cost-effective high-volume sending

SMTP Settings

Setting	Value
SMTP server	email-smtp.us-east-1.amazonaws.com (or your region)
SMTP port	587 (STARTTLS) or 465 (SSL)
Encryption	STARTTLS or SSL
Authentication	SMTP Username + SMTP Password
Username	Your SES SMTP Username
Password	Your SES SMTP Password

SMTP URL Format: smtps://smtp_username:[email protected]:587

Domain Authentication Setup

SPF Record:

v=spf1 include:amazonses.com -all

DKIM Setup:

1. In AWS SES console, go to Configuration > Verified identities

2. Select your domain and enable DKIM

3. Add the provided CNAME records to your DNS

DMARC Record:

_dmarc.yourdomain.com  IN  TXT  "v=DMARC1; p=quarantine; rua=mailto:[email protected]"

Amazon SES Specific Notes

• Sandbox Mode: New accounts start in sandbox mode with sending restrictions

• Region Selection: Choose the region closest to your users

• Reputation Monitoring: Monitor bounce and complaint rates in SES console

HubSpot

Recommended for: Marketing automation and CRM integration

SMTP Settings

Setting	Value
SMTP server	smtp.hubspot.com
SMTP port	587 (STARTTLS)
Encryption	STARTTLS
Authentication	Username + Password
Username	Your HubSpot email
Password	Your HubSpot password

SMTP URL Format: smtps://your_email:[email protected]:587

Domain Authentication Setup

SPF Record:

v=spf1 include:_spf.hubspot.com -all

DKIM Setup:

1. In HubSpot, go to Settings > Website > Domains & URLs

2. Connect your domain

3. Add the provided CNAME records to your DNS

DMARC Record:

_dmarc.yourdomain.com  IN  TXT  "v=DMARC1; p=quarantine; rua=mailto:[email protected]"

HubSpot Specific Notes

• Connected Domain: Domain must be connected in HubSpot settings

• Marketing Hub: Some features require Marketing Hub subscription

• Contact Management: Integrates with HubSpot CRM for contact tracking

Generic SMTP Providers

For other SMTP providers not listed above, follow this general configuration pattern:

SMTP Settings Template

Setting	Value
SMTP server	smtp.yourprovider.com
SMTP port	587 (STARTTLS) or 465 (SSL)
Encryption	STARTTLS (preferred) or SSL
Authentication	Username + Password or API Key
Username	Your email or username
Password	Your password or API key

Domain Authentication Template

SPF Record: Contact your provider for their SPF include directive DKIM Setup: Enable in provider settings and add required DNS records DMARC Record: Use the standard DMARC format shown above

Troubleshooting & Monitoring

Common Issues

Authentication Failures:

• Verify username and password are correct

• Check if two-factor authentication requires app passwords

• Ensure SMTP AUTH is enabled for the account

Connection Issues:

• Verify SMTP server address and port

• Check firewall settings allow outbound connections

• Test with telnet: telnet smtp.provider.com 587

Delivery Issues:

• Check SPF, DKIM, and DMARC records are properly configured

• Monitor bounce rates and spam complaints

• Verify sender reputation with tools like mail-tester.com

Monitoring Tools

Email Testing:

• mail-tester.com: Test spam score

• MXToolbox: DNS and deliverability testing

• DMARC Analyzer: DMARC report analysis

Provider-Specific Monitoring:

• Office 365: Message Trace in admin center

• SendGrid: Email Activity dashboard

• Mailgun: Logs and analytics in dashboard

• Amazon SES: Sending statistics in AWS console

Best Practices for Monitoring

• Set up DMARC reporting to monitor authentication failures

• Regularly check bounce and complaint rates

• Monitor sender reputation scores

• Test email delivery to major providers (Gmail, Outlook, Yahoo)

• Set up alerts for delivery issues

Summary Checklist

Before going live with your email configuration:

Technical Setup

• SMTP credentials configured in Buzzy

• SPF record includes your provider's directive

• DKIM enabled and DNS records added

• DMARC record added (start with p=none for testing)

• Test email delivery to major providers

Monitoring Setup

• DMARC reporting configured

• Provider-specific monitoring enabled

• Bounce and complaint tracking set up

• Regular deliverability testing scheduled

Content and Compliance

• Professional "From" address configured

• Unsubscribe mechanism implemented

• Email templates tested for spam triggers

• Sending volume gradually ramped up

Documentation

• SMTP settings documented for your team

• DNS records backed up

• Provider account credentials securely stored

• Monitoring procedures documented

Additional Resources

Official Documentation Links

• Microsoft: DKIM in Microsoft 365

• Microsoft: SPF in Microsoft 365

• Microsoft: DMARC in Microsoft 365

• SendGrid: Domain Authentication

• Mailgun: Domain Verification

• Amazon SES: Authenticating Email

Email Deliverability Resources

• Return Path Email Deliverability Guide

• DMARC.org - Official DMARC specification

• Email on Acid - Email testing platform

• Litmus - Email testing and analytics

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Email deliverability is an ongoing process. Start with basic authentication (SPF, DKIM, DMARC) and gradually implement advanced monitoring and optimization based on your sending volume and requirements.