Our company used Zoho about 2 years ago and always had trouble understanding why a great deal of our emails from Zoho CRM and Zoho Marketing Automation ended up in the recipient's spam folder regardless of the email content and despite having our domain set up correctly in Zoho.

For the last 12 months, we have been using MailerLite as our email marketing which has a much higher delivery rate. At the time we migrated to MailerLite we also instantly saw a much higher open rate by roughly 15%. That's a huge jump!

Keep in mind, that when a recipient's email server indicates the email has been delivered, it does not mean the email was delivered directly to the inbox. Instead, it could have very well been delivered to the recipient's spam or promotions folder. So the open rate was a huge indicator that there was an issue within Zoho.

Unfortunately due to other issues with MailerLite, we decided to give Zoho another try recently.

After doing a bit more testing we have found that even though Zoho CRM and Zoho Marketing Automation claim your domain is verified, it still does not have the proper SPF alignment included in each email's header. Only Zoho Mail will have the proper DKIM and SPF signatures. Essentially what happens in each of Zoho's other apps is that your email claims it is being sent from one domain but the SPF record is signed by another. 

This misalignment causes your emails to have a lower security scoring and results in a higher likelihood of the emails being routed to the recipient's spam folder or potentially even being rejected completely.

In email marketing, this is a huge problem. Keep in mind that recipients won't go searching through their spam just to see if you happen to send them an email that day. Even worse if you've built Zoho Campaigns or Zoho Marketing Journeys that utilize email open conditions your journey efforts will be completely lost from the start.

I contacted support and was essentially told not to worry about it because when an email is sent from Zoho Transmail servers for any Zoho app other than Zoho Mail, only the DKIM signature matters. This is a completely false statement as mail services treat each incoming email the same. Trust me there's no mail server out there saying "Hey let's make an exception for Zoho." Quite the opposite as we have also discovered that Zoho is on at least one delivery blacklist. 

From the developer's aspect, I understand why Zoho has chosen to design their system this way. It's the easy way of development. But I also know that they need to be a bit more upfront about the issue rather than simply implying that the domain is highly deliverable and the SPF records don't matter.

For us, the only solution to fix Zoho's design shortcomings is to either purchase a dedicated IP from Zoho or find a new provider with a better design. 

If you're scratching your head about why your open rate is lower than you expect even when you keep your contact list clean and maintained, you can thank Zoho's design.