There are hundreds of reasons that mailbox providers could place your email in the spam folder.
Here are the most common reasons we see and how to fix them!
Sending From a Public Domain
If you are sending messages from a free domain like gmail.com, yahoo.com, etc., your messages will likely go to the spam folder. You'll want to be sure to send mail from a domain that you own and that matches your branding.
Sending Internal Mail
Are you sending messages to the same domain that the message is coming from? For example, sending from email@example.com to firstname.lastname@example.org. If so, it's common for these internal messages to go to spam. This is because your mailbox sees that it's receiving a message from itself, but it knows that it didn't send the message (ConvertKit did). This makes your mailbox think it's being spoofed, and it sends the message to spam.
If you're just sending internal mail to test your messages, I'd recommend using a free email like gmail.com. If you need to send mail internally outside of testing, you'll want to have the person who manages mail for your domain allowlist ConvertKit's IPs.
If the domain you use to send mail has a DMARC policy but you haven't verified the domain in ConvertKit, your messages will likely go to spam. Check out this article for instructions on how to ensure your ConvertKit messages pass DMARC.
If you collect subscribers through online signup forms, there's a chance you're being affected by listbombing. We explain what listbombing is, and how to fix it, here: https://help.convertkit.com/en/?q=listbombs
List Health & List Collection
If all of the technical pieces above are covered, list health and list collection are the next most important factors to determine deliverability. Be sure that:
Everyone on your list gave direct consent to receive email marketing from you
Your cold subscribers are cleaned from your list regularly
Your forms are secured with double opt-in
To learn more about why messages go to the inbox or spam folder, check out our Deliverability 101 article.