Mandrill is a transactional email platform from Mailchimp, a paid add-on for monthly Mailchimp accounts. Any paid monthly Mailchimp plan will satisfy the new requirements.
Create account with Mailchimp at first:
Choose your plan:
Follow the instructions:
Once you fill all fields with information, you’ll get an activation link on your email:
2. When you finish with registration, go to Account → Transactional → Choose Demo or Plan version:
3. Click Launch App:
4. Type in your domain name and click Add:
5. To verify your domain, click View details and type in your domain email. You will get a verification link on your email, just click it to complete a domain verification:
6. To complete a verification, you need to add DKIM and SPF records.
These TXT records could be stored in two places:
either cPanel account;
or your domain registrar account.
It depends on the way you propagated your domain name. If you changed DNS – find your TXT records in cPanel, if you changed IP – you need to find them in your domain registrar account.
Find both instructions below, but you need to follow only one option.
Option 1 – if your TXT records are stored in cPanel:
Click Add Record:
Click View DKIM settings in your Mandrill account → Copy Name and Value and paste them in TXT record in cPanel:
Click View SPF settings in your Mandrill account → Copy Name and Value and paste them in TXT record in cPanel:
Refresh your Mandrill account page – it’s verified:
Option 2 – if your TXT records are stored in Domain registrar account:
Add new TXT record. Put in the Host and Value fields Name and Value from your Mandrill account.
7. Now go to Settings → SMTP & API credentials → Create new API key:
8. Copy this API key and insert in your WordPress admin area:
9. Click Save Changes. It’s done!
NOTE: Since your account is on a free trial plan, your account is limited to the restrictions of a demo account.
This means that your domains you plan to send from must be verified and authenticated (have the required SPF and DKIM records), and you can only send to recipients at any of those domains you verify and authenticate. So, for example, you can send to and from domains on your sending domains page with three green checkmarks at this time without getting the 'recipient-domain-mismatch' error.
For reference: