It can be very difficult to diagnose why a particular email ends up in the spam folder. Every recipient email server is different, and most never reveal any information about why they have marked an email as spam (to prevent people from working around their filters). Some email services or spam filters can be particularly opaque. That being said, there are steps you can take to help your message land in the inbox:
If your account has a history of high spam complaint rates (anything over 0.1%), high hard bounce rates (anything over 5%), or high unsubscribe rates (anything over 1%), your email reputation might be suffering. Spam filters often take into account past performance and email reputation when judging an email. Your list might be too old or the contacts might not be opt-in. Your message may not be relevant to what your subscribers originally signed up for.
Take a look at our mailing list requirements and, if necessary, make changes to your list to remove contacts that are too old or not opt-in.
Another metric many spam filters consider is engagement. In other words, have your recipients opened previous emails from you? Or have most of them just been thrown away or left unread? Consider retiring contacts from your list that have not engaged with you in a long time. This will help boost your open and click rates and improve the deliverability of future campaigns.
Run your message through our Spam Test (choose Message > New Spam Test from the menu bar at the top of the screen). The Spam Test can help reveal characteristics of your message content that might be triggering spam filters.
If your email landed in the spam folder, try moving it out of the spam folder and back to the inbox. This can be a signal to the spam software that this and future messages like it should not be considered spam.
If the domain name that you are using in your "From" address makes use of SPF or Sender ID, make sure that your DNS settings have been updated to allow Direct Mail to send email on your behalf. If the aforementioned alphabet soup doesn't make any sense to you, then you can probably ignore this item—our system takes care of these settings for you automatically.