Frequently asked questions
Short answers to the questions we hear most, with links to the full guides.
Updated October 23, 2026
Do I need my own domain?
Yes. SendDuo sends from your own domain, like hello@yourshop.com, and you verify it once by adding a few DNS records. Free addresses like Gmail cannot be used to send. See Verify your sending domain.
Do I need a credit card to start?
No. The Free plan includes 2,000 emails a month and up to 1,000 contacts. See Plans and billing.
Why didn't my campaign send right away?
For new accounts, we review the first campaign before it sends. This usually takes a few hours, and we email you when it is sent. After that, campaigns send straight away. See Create and send a campaign.
Why can't I see my popup again?
A popup shows to each visitor once, then waits the number of days you set in Show again to the same visitor after (days) (14 unless you change it). It also stops showing to visitors who signed up, or who came to your site from one of your emails. To see it again, open your site in a private browser window. See Create a popup or signup form.
Can I use SendDuo without Shopify or WordPress?
Yes. You can import your contacts, send campaigns, run the Welcome automation and add sign-up forms to any website. Automations that use orders or carts (Post-purchase, Win-back and Abandoned cart) need a connected store. See Add forms to any website.
Where do my sign-ups go?
Everyone who signs up through a form is added to Contacts as subscribed, and your Welcome automation starts for them if it is on. If the form uses double opt-in, they are added once they confirm by email. See Automations.
Can I import my list from Mailchimp?
Yes. Export your contacts from Mailchimp as a CSV file, then go to Contacts and click Import CSV. SendDuo recognizes Mailchimp's columns, like Email Address, First Name, Last Name and Tags. See Import contacts.
Do contacts who unsubscribed count toward my plan?
No. Only subscribed contacts count. Unsubscribed and bounced contacts never count.
Will I be charged extra if I go over my emails?
No, never. A campaign that would go over your monthly allowance does not send, and automated emails wait. Your allowance resets on the 1st of each month (UTC), or you can upgrade or buy an email pack. See Plans and billing.
Can I cancel anytime?
Yes, from the Billing page. Your plan stays active until the end of the period you paid for, then moves to Free. See Plans and billing.
How do I keep my emails out of spam?
Verify your domain, send only to people who asked for your emails, and add some text, not just images. See Stay out of spam.
Is my data safe?
Every connection uses HTTPS, and your data, images and backups are stored encrypted. We never sell your customers' data. Read the details on our Security page.
How do I contact support?
Email support@sendduo.com. Inside SendDuo, you can also open Send feedback to tell us about an idea or a problem. We read every message.