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Here are the best ways to stop emails from being put in the junk mail folder.
SPF - Sender Policy Framework records help reduce the chance of your domain being spoofed in spam messages. It can also increase the deliverability of e-mail to external providers such as Gmail and Outlook. You can add them individually by adding a TXT record to the domain with the data:
v=spf1 include:spf.stackmail.com a mx -all.
This tells other providers that CreateTheWeb is a confirmed sender of your domain's emails.
DKIM, like SPF, is a standard that enables a specific aspect of the email sending process to be authenticated. The premise of DKIM is to check that an email is really from the domain or sender that it said it was sent from and if it has been altered in any way in transit.
You can add one by going to the hosting package for the domain and to the DomainKeys section. You then need to select the domain you wish to add on to and add a Selector. This can be any value or name you like. It’s simply a field to identify the DKIM record. Then select Add Signature. If your nameservers are with us we'll automatically add this as a TXT record for you. If your name servers are elsewhere you'll need to go to 'Options' for the newly created DKIM and copy the DNS Name and DNS Value to a TXT record with your current DNS provider.
If incoming emails are the issue then you can whitelist the mail in the Junk Mail Filters section of any hosting package. In the Junk Mail Filters section, you can set the general filtering level to tell us how strict we should be with incoming spam filtering.
If you just want to allow a particular address this can be done by whitelisting it for a domain or the mailbox on the package. If you want to white list a single mail address then you would need to whitelist 'firstname.lastname@example.org' and if you want to whitelist a whole domain then you would want to whitelist '*@thedomain.com'. This will allow mail from the address/domain to bypass our spam filtering.