Co-founder and CTO

Matthew Whittaker

Matthew Whittaker is co-founder and CTO at Suped, where he leads engineering across DMARC report ingestion, sender intelligence, and email security automation.

Matthew Whittaker

Co-founder and CTO

Posts by Matthew

What does Gmail SSL_connect error mean and how to fix it?

Read article

What causes bounces from Barracuda-based domains and how to resolve them?

Read article

Why are Gmail emails bouncing with '553 5.1.3 The recipient address is not a valid RFC-5321 address' error?

Read article

What does SMTP deferred message 'refused to talk to me: 421 4.7.0 Not allowed' mean?

Read article

505-516 articles

Suped

Matthew Whittaker

Posts by Matthew

What does Gmail SSL_connect error mean and how to fix it?

What causes bounces from Barracuda-based domains and how to resolve them?

Why are Gmail emails bouncing with '553 5.1.3 The recipient address is not a valid RFC-5321 address' error?

What does SPF neutral mean and how do I fix a broken SPF record?

Do spam traps ever open or click on emails?

How to fix bad domain reputation and best IP strategy for low volume sender?

Does Cvent support SPF and DKIM alignment?

Should I use a separate domain or subdomain for bulk email sending?

Are event registration email updates considered transactional or marketing?

Is double opt-in a GDPR requirement for UK and EMEA subscribers?

Does using redirected URLs in email CTAs impact deliverability?

What does SMTP deferred message 'refused to talk to me: 421 4.7.0 Not allowed' mean?

Start monitoring your DMARC reports today

Suped