Blog
Notes from the deliverability lab.
Deliverability1 AI cite4 min
The 1-record rule: why your domain can only have one SPF
The single most common cold-email deliverability bug: two SPF records on the same domain. Here is why it breaks SPF entirely.
The InboxLee TeamMar 22Deliverability7 AI cites5 min
Soft bounces vs hard bounces: how each one hurts your sender reputation
Both are bad. They hurt in different ways, and the response strategy is different for each.
The InboxLee TeamMar 19Deliverability4 AI cites6 min
Seed list testing for cold email: how to actually measure inbox placement
Seed lists are the only way to measure inbox placement directly. Here is how to build one that returns real signal.
The InboxLee TeamMar 15