Potomac1050.mktomail

[Tamela Vandonsel]

Isthe part underlined in red specific to our company? Or does it just mean the real sender is Marketo - or a particular shared Marketo IP? I'm asking because I've seen that same email address reported as spam in bounce/email suspend causes. We're wondering if we should look into getting a dedicated IP address to lessen instances of being interpreted as spam. In other words, if a filter decides that potomac1050.mktomail.com is a spammer is that a response to my client's company or to a Marketo shared IP address?

Google & other email providers, and unfortunately Marketo too, tend to dumb down the very important distinction between envelope info & email headers. This causes all manner of confusion with no upside. I wish everyone would convey the technical truth, fewer things would break that way.

Blacklists aren't just based on that hostname, since a hostname is easily changed. A blacklist will eventually spread to cover anything coming from an IP address or even from a whole IP subnet (block of contiguous IPs). You can affect other people, or they can affect you.

Yet lots of (most of, AFAIK) Marketo's customers get by with a shared IP. The shared knowledge that you may affect other people's deliverability is a check on bad behavior. And not everyone can send from a dedicated IP, it's not only financially unfeasible but technically impossible.

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