Email syntax
Catch malformed addresses before sending. A correctly formatted address is only the first check; it does not establish that the mailbox exists.
PRE-SEND EMAIL & SMS PROTECTION
Catch risky email addresses, check your sender setup and validate phone numbers before your messages go out. Sendvio brings these checks into your campaigns and automated follow-ups.

EMAIL ADDRESS VERIFICATION
Protect the audience you have worked to build. Sendvio checks email addresses before sending, using separate validation infrastructure to help protect your sending reputation during verification.
Catch malformed addresses before sending. A correctly formatted address is only the first check; it does not establish that the mailbox exists.
Check for invalid, inactive or parked domains and invalid email accounts. Evaluate the receiving server’s response before attempting delivery.
Verify the domain’s mail routing records and whether a mail server is configured to accept incoming email. A website can exist without a working email service.
Check whether a mailbox exists and can receive email. Detecting permanent failures in advance helps keep avoidable bounces out of your campaigns.
Identify temporary inboxes that can disappear shortly after signup. These addresses are unreliable for an ongoing relationship with your customers.
Detect addresses associated with spam-trap risk. Sending to these addresses can damage the reputation that supports delivery to your genuine customers.
Identify servers that accept any address at a domain. That response does not establish whether a particular person’s inbox exists.
Detect repeated email addresses to avoid processing or messaging the same address more than once.
EMAIL AUTHENTICATION & SENDER REPUTATION
A valid recipient is only part of email deliverability. Your domain configuration, sending history and content matter too. Sendvio brings these protections into the same platform.
Sendvio checks domain authentication alignment before email campaigns and automations, helping you identify sender configuration problems before they affect your messages.
Detect duplicate DMARC records, generate a combined SPF record for multiple email platforms and get steps to resolve configuration issues.
Build or resume email sending gradually. Sendvio adjusts sending volume automatically to support your domain’s sending reputation.
Identify excessive email length and split oversized images into smaller sections. Address content and layout issues before sending your campaign.
SMS PHONE NUMBER VALIDATION
A number saved in a customer profile may belong to a mobile phone or a landline. Sendvio checks the line type before SMS sending to help avoid attempts to phones that cannot receive text messages.
Identify the type of phone number on the customer record. A number that works for voice calls is not necessarily suitable for an SMS campaign or automation.
Detect landline numbers before attempting to send a text. This helps reduce unnecessary attempts to destinations that cannot receive SMS.
Phone numbers found to be invalid are marked in your Sendvio database, keeping the result connected to the customer record.
Phone validation is included in the Email + SMS plan. It checks the phone number for SMS sending; email domain and mailbox checks apply separately to email.
PART OF THE SENDING WORKFLOW
Check the audience and sending setup before a campaign or automated follow-up goes out. Email and SMS protections address different problems, with validation results kept on the customer record for future sends.
Use current customer data, subscription status and relevant segments. Verification complements good audience practices; it does not replace permission to send.
For email, check recipient addresses and sender authentication. For SMS, assess number suitability and line type. Keep each channel’s result distinct.
Invalid addresses and numbers are marked in the database rather than deleted. Use those results to avoid repeating preventable sending attempts.
DELIVERABILITY QUESTIONS
A hard bounce is a permanent delivery failure, such as a nonexistent mailbox. Pre-send verification helps identify these problems before your campaign encounters them. Temporary failures, such as an unavailable receiving server, can still occur later.
No. A catch-all server accepts addresses at its domain without confirming that each individual mailbox exists. It is a risk signal, not proof that every address on that domain is invalid.
No. Address verification reduces avoidable bounces, while authentication and warming support your email reputation. Inbox placement also depends on recipient engagement, content and the receiving provider’s filtering.
No. A mobile line type alone does not confirm current reachability. Carrier filtering and network conditions can still affect SMS delivery.
Invalid email addresses and phone numbers are marked as invalid in your Sendvio contact database.