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An invalid or missing email address or phone number (in the case of SMS messages)
Blocked email messages - if you or your email provider has flagged emails from VTEvents as spam, they may not come through. Your email provider may be the best people to speak to in this instance, or otherwise trying a different email address may be of assistance.
Bounced email accounts - if your account is full/at capacity/unable to accept mail, messages won’t get delivered.
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Bounced email accounts - if your account is locked/closed/invalid, or there are other server issues, email messages won’t be able to get delivered. If this continues to occur, we may flag your account as having issues accepting mail, and won’t continue to sent it mail.