Question:

I use Microsoft Outlook for all my business emails. Since I send out emails with a photo signature of my company’s logo, am I risking winding up in customers' spam folders? —Mark Lambert

Answer:

While it’s difficult to tell you with any certainty that your emails won’t end up in your customers’ spam folders, chances are you’re probably OK as long as the image isn’t too big, says Ronen Yaari, president of OpenMoves, a boutique email marketing firm in Huntington, N.Y. Besides spam words like “free” or “compare,” Internet service providers, or ISPs, generally look at two things before they flag your email and send it to a spam folder: the ratio of images to other content and whether or not your email is coming from a third party, he says.

Since an ISP can detect spam words and send emails that include them straight to spam folders, spammers have figured out that if they embed those words into an image, they can trick an ISP into letting it in. However, over time, ISPs have gotten wise to those tricks. Now, when they find an email that is mostly an image, they’ll block it or at least send it to people’s junk folders before routing it to their inboxes.

Likewise, ISPs are leery about permitting emails that stem from a third-party provider. While many legitimate bulk email providers can work around this obstacle, if you want to ensure that someone receives your message, be sure to send it yourself, says Yaari. (For our story on how to stay out of customers’ spam folders, click here.)