I run a website (seatgeek.com) that sends a lot of transactional email to users--account updates, alerts, etc. It's important to us that our domain remains clean in the eyes of spam filters.

We'd like to roll out an email marketing campaign. It's nothing particularly spammy, but this would be the first time we ever emailed to people who hadn't expressly asked to receive email from us. It's to market a new product we built to a specific niche of professionals.

In order to protect our domain in the eyes of spam filters, we're considering sending the marketing email from an alternative domain. The alternative domain is an alternative landing page we sometimes use for this new product.

Is there any way this could backfire on us? Does it seem like a particularly poor idea?