The email service is blocked

If you or one of your attendees sees the message "The email service is blocked, please use a different email address", that mail provider is on our blocklist. Our system sends nothing to addresses registered with it.

We block providers we cannot deliver to reliably. Sending into a domain that bounces our messages, or that generates complaints, damages delivery for every other user on the platform.

Why a mail service gets blocked

We watch the quality of the addresses used in our system. Three things get a provider blocked: a technical misconfiguration, a security risk, or a run of spam complaints.

1. The mail service is configured incorrectly

A mail service has to meet the usual standards before anything sent to it can be delivered and authenticated. When its settings are wrong, we block it rather than watch message after message fail. The common faults:

• SPF, DKIM and DMARC records are missing or invalid. Those records are how a receiving server confirms that a message really came from the domain it claims, and without them spoofing and phishing are easy.
• MX records are wrong or absent. They decide which servers handle incoming mail for a domain, so when they are broken there is nowhere for our mail to go.
• The domain is temporary or unverified. Some services hand out disposable addresses, which makes them unreliable to send to.
• The provider's IP address sits on a reputation blocklist such as Spamhaus, Barracuda or Proofpoint.

None of that is fixable from your side. Ask the administrator of the mail service to check the settings and correct them.

2. Domains that refuse mail or never answer

We also block a service that rejects the messages we send outright. The same goes for one with a policy against automated notifications, or one that never answers a delivery attempt at all.

This catches a lot of corporate mail. Companies run internal servers meant only for internal correspondence, and those servers drop anything from a sender they do not recognise. If yours works that way, ask your administrator whether mail from our system can be let through.

3. A high number of spam complaints

This is the most common reason of the three, and it starts with the recipients themselves. Once enough people mark our messages as spam, their provider begins blocking us, and that provider then ends up blocked on our side as well.

Most of those complaints trace back to attendees who never signed up in the first place. Someone added to a list without agreeing to it reads the invitation as unsolicited, and reporting it takes one click.

A domain that public blocklists already flag for bulk unsolicited mail gets blocked on that basis alone.

What this means for hosts and attendees

An attendee with a blocked address gets nothing from us. No registration confirmation, no reminder, no access link. The host loses part of the audience for a reason that has nothing to do with the webinar itself.

If a mail service keeps generating complaints, the block stays in place until someone asks us to look at it again.

What to do if your address is blocked

1. Use a different mail service

An address with Gmail, Outlook, Yahoo or another well established provider will go through. If you just need the person into the webinar today, this is the route.

2. Check the settings of your mail service

If you would rather keep the address you have, ask the administrator of the mail service to confirm that:

• SPF, DKIM and DMARC are set up, so messages can be authenticated
• MX records are correct and the domain does accept incoming mail
• the domain is not listed on a public blocklist, which you can check with MXToolbox

3. Ask us to review the block

Administrators of a blocked mail service can open the online chat and ask us to look again. Give us the domain name and the addresses that are not receiving mail, confirmation that the service meets the requirements above, and anything else that explains why the domain should not be blocked.

Requests from ordinary users of a blocked service cannot be processed. The review has to come from someone with administrative control over the domain.

How to avoid a block in the future

If you run webinars regularly and depend on our mail:

• point attendees towards well established mail providers when they register
• add only the people who agreed to hear from you, because addresses added without consent are what produces complaints
• ask attendees to allowlist our messages, for example by moving one out of the Spam folder into the inbox
• keep a test address of your own on two or three of the big providers, and check now and then that an invitation really arrives there

Why we block at all

A provider on the list is one we could not deliver to reliably anyway. Keeping those domains out means fewer bounces and a sending reputation clean enough that everyone else's invitations land in the inbox rather than the spam folder.

If you still have questions, open the online chat and ask us.

Frequently asked questions

Is my own address blocked, or the whole mail service?

The whole mail service. The message means the provider that hosts the address is on our blocklist, and our system sends nothing to any address registered with it. Another address at the same provider will fail in exactly the same way, so what gets through is an address somewhere else, with Gmail, Outlook, Yahoo or another well established provider.

Does the block lift by itself once the mail service is fixed?

No. The block stays in place until someone asks us to look at it again. That request has to come from someone with administrative control over the domain, because requests from ordinary users of a blocked service cannot be processed. Open the online chat with the domain name, the addresses that are not receiving mail and confirmation that the service now meets the requirements.

An attendee registered but never got the access link. Could a block be the reason?

It can be, because an attendee with a blocked address gets nothing from us, so no registration confirmation, no reminder and no access link. Nothing on the webinar side is at fault, and the host simply loses part of the audience. If the address sits on a company domain, ask their administrator whether mail from our system can be let through.

Our company runs its own mail server. Why would that be blocked?

Because a lot of corporate servers are built for internal correspondence only and drop anything from a sender they do not recognise. We also block a service that rejects our messages outright, one with a policy against automated notifications, or one that never answers a delivery attempt at all. Ask your administrator whether mail from our system can be let through.

My webinar is today. Can I still get that person in?

Use a different mail service for them, because an address with Gmail, Outlook, Yahoo or another well established provider will go through. The other two routes, checking the settings of the blocked mail service and asking us to review the block, both need the administrator of the domain.