About email delivery

LimeSurvey Cloud sends your invitations and reminders through its own mail server, unless you set up your own SMTP server. When LimeSurvey shows an invitation as sent, the email has left the server. Whether it reaches the inbox depends on the mail servers and spam filters of the recipients.

Make your invitations trustworthy

• Align the domains. Send from an address on the same domain as your survey. For example, send from mail@yourdomain.net when the survey runs on survey.yourdomain.net. On plans with alias domains, see How do I change my survey site domain?
• Send through your own mail server. Use the SMTP server of your domain and set up SPF, DKIM and DMARC for it. See Set up how your survey site sends email.
• Invite people who agreed to be contacted. Unsolicited emails are marked as spam more often.
• Keep the text clear. Use a clear subject, avoid promotional language and keep the opt-out link {OPTOUTURL} in the template.
• Test first. Send a test to a mail testing service before a large mailing.

When invitations do not arrive

1. Ask the recipients to check their spam and quarantine folders. Company mail servers can hold bulk mail without telling the recipient. Ask their IT team to allow your sender address.

2. Compare the domains of the recipients. If addresses at some domains get the invitations and others never do, the receiving domain filters them. This is fixed on the side of the recipient.

3. Check the Email status of the participants in the participant list. With Bypass participants with failing email addresses on On, participants whose status is not OK get no email.

4. If you send through your own SMTP server, check that its settings still work. Microsoft 365 no longer accepts a username and password for SMTP and needs an OAuth setup.

Note: A test email that arrives does not prove that bulk invitations work. Test emails and invitations take different paths.

Mark bounced addresses automatically

An invitation to an address that does not exist comes back as a bounce message. LimeSurvey can read these messages from a mailbox and mark the participants, so later mailings skip them.

1. On the Survey participants page, click Invite & remind and then Bounce settings.

2. Enter the Survey bounce email address (1), the mailbox that receives the bounce messages.

3. Under Used bounce settings (2), choose Use settings below, or Use global settings to use the bounce settings of your site.

4. Enter the details of the mailbox (3): Server type (IMAP or POP3), Server name & port, User name, Password and Encryption type.

5. Click Save (4).

After a mailing, click Invite & remind and then Start bounce processing. LimeSurvey checks the mailbox and changes the Email status of participants whose invitation bounced. With Bypass participants with failing email addresses on On, the next reminder skips them. Start bounce processing is greyed out while Used bounce settings is None.

Contact support

If invitations show as sent but arrive nowhere, neither in the inbox nor in spam, while test emails work, the cause can be on the LimeSurvey Cloud platform. Contact support and include the survey ID, when you sent the invitations, roughly how many, whether test emails work, an example address that did not receive the invitation, and a screenshot of any error.

Support may ask for your written consent to access your account. Replying "I agree" is enough.

Next steps

• Send invitations and reminders
• Set up how your survey site sends email
• Overview: Share

FAQ

Does sent mean the invitation arrived?

No. It means the email left the mail server. Spam filters and quarantines on the side of the recipient can still hold it.

Can I send invitations from my own mail server?

Yes. See Set up how your survey site sends email.

Only some recipients get the invitation. Why?

Most likely their mail servers filter it. Ask the recipients, or their IT team, to allow your sender address.