I know this email address is valid, but it hard bounced
Valid email addresses can hard bounce for many reasons. Reading bounce headers (SMTP replies) can provide insight on what caused an address to hard bounce.
Valid email addresses can hard bounce for many reasons. Reading bounce headers (SMTP replies) can provide insight on what caused an address to hard bounce.
Even permission-based audiences can fall prey to aggressive spam filters, which we estimate block 10-20% of email from subscribers' inboxes.
When an email is rejected by an email server, it's called a bounce. Learn about the different types of bounces and how to abide by spam laws.