It can be tricky to diagnose the exact reason why mail is landing in spam. Some of the most common causes are:
DNS records such as SPF or DMARC/DKIM haven't propagated or authentication fails.
Your ImprovMX alias isn't set up properly in your mail client.
The content of your email is causing the recipient's mail provider to filter your messages.
Your domain or sending IP address is listed on a block list.
DNS record propagation and SPF/DKIM authentication
The first thing to check is whether or not your DNS records have propagated. You can use tools like https://check.mx and https://mxtoolbox.com to see if your records are live. If you see your records using these tools, they're live! If not, and you've recently set or changed DNS records, they may still be propagating.
**Ultimately, this propagation period is dependent on your DNS provider, which is commonly your domain registrar. If the records have not propagated, and you've waited over 48 hours, we suggest reaching out directly to them to see what the hold up is.
Check if your mail is passing DKIM and SPF. If you receive aggregate reports (more here) check those first. If you're not receiving reports, no problem, you can check mail headers directly. In the recipient mailbox (the one that is filtering to spam) view the original email with all headers intact: http://help.improvmx.com/en/articles/5401249-how-to-view-email-headers
Check your alias settings
Often, especially with Gmail aliases, it can help to simply re-create the alias. Delete your current alias and re-create it following one of the above guides.
Check the content and subject line of your email. Many mail providers will filter mail that it suspects as spam. Things that factor into this filtration are HTML-based emails, solicitation attempts, heavy usage of links, disallowed message attachments, image-only emails, etc. Many mail providers will have support articles regarding how they filter mail.
If possible, test the same email outside of ImprovMX. If the email goes through without being considered as spam, let us know!
Use tools like the following to check Spam Assassin (employed on the ImprovMX level) scores: https://spamcheck.postmarkapp.com/
Domain or origin is block listed
Run your domain and origin IP address/service through common block lists such as https://check.spamhaus.org/
Nothing is helping and mail is still landing in spam
We'll help diagnose possible issues with mail landing in spam. Drop us a line with the following information to help expedite the troubleshooting process:
Are you using Gmail SMTP or ImprovMX SMTP to send mail?
Are you getting flagged within ImprovMX (displayed in your logs) or the destination mailbox?
Do all of your messages land in spam for all recipients? If not, do you notice the spam-flag occurring on certain recipients in particular? (I.E. Outlook or Yahoo recipients).
Are you able to retrieve the headers (http://help.improvmx.com/en/articles/5401249-how-to-view-email-headers) of one of the spam-flagged emails? If so, please attach them via copy + paste to your support request.
Any other information you may find pertinent!