You must include _zoho.com_ in your SPF record to guarantee that Zoho is permitted to send emails on your behalf. SPF is a DNS-based filtering system that mail gateways use to identify legitimate mail servers.
Open your DNS registrar’s account
Navigate to the domain for which you want to modify/add your SPF record
If you already have an SPF record for that domain:
If you are using Zoho Campaign,
Add the following include mechanism to your pre-existing SPF record:
include:zcsend.net
In case you are using Zoho Mail,
Add the following include mechanism to your pre-existing SPF record:
include:spf.zoho.eu or, include:zoho.in
Kindly consult with Zoho support in order to have better clarity on which include statement you should add for Zoho. Your modified SPF record will look something like this:
v=spf1 include:_spf.google.com include:zoho.in -all
Note: Make sure your domain has only one SPF record and that IP and include methods for third-party email services and applications are added to the same SPF record. SPF will be invalidated if you publish duplicate SPF records in your DNS.
If you don’t have an SPF record for your domain, simply add a TXT record with the value:
v=spf1 include:zoho.in -all
Finally, lookup and validate your SPF record to ensure your SPF record is error-free and valid.