Use UpdateContactMessageCategoryPreference to opt a contact out of or back into a Message Category.

Contacts are available for all Message Categories by default unless an active category-level opt-out exists. Other suppression, unsubscribe, bounce, compliance, or targeting rules can still prevent sending.

This action updates one Message Category preference only.

Notes

• Provide one contact identifier: ContactId, Email, or ID. If more than one is supplied, resolution prefers ContactId, then ID, then Email.
• ID is the remote key. Element text is the remote ID; optional source is the remote system name.
• MessageCategoryId must be an active (non-archived) Message Category in the authenticated brand.
• PreferenceAction is case-insensitive (OptOut / OptIn).
• When using PostInformzMessage, place the ActionRequest XML in the SOAP <x> CDATA body.

Details

Opt Out

Opts a contact out of a Message Category. Idempotent if already opted out.

Request

<ActionRequest xmlns="http://partner.informz.net/aapi/2009/08/">
 <Brand id="2001">Example Brand</Brand>
 <User>apiuser</User>
 <Password>password</Password>
 <Actions>
  <UpdateContactMessageCategoryPreference>
   <Contact>
    <ContactId>10001</ContactId>
   </Contact>
   <MessageCategoryId>11</MessageCategoryId>
   <PreferenceAction>OptOut</PreferenceAction>
  </UpdateContactMessageCategoryPreference>
 </Actions>
</ActionRequest>

Alternate contact identifiers:

<Contact>
 <Email>user@example.com</Email>
</Contact>

<Contact>
 <ID source="PartnerSystem">REMOTE-42</ID>
</Contact>

Response

<ActionResponse xmlns="http://partner.informz.net/aapi/2009/08/">
 <Brand id="2001">Example Brand</Brand>
 <User>apiuser</User>
 <Responses>
  <UpdateContactMessageCategoryPreference>
   <ActionStatus>
    <Status>success</Status>
   </ActionStatus>
   <ContactId>10001</ContactId>
   <Email>user@example.com</Email>
   <MessageCategoryId>11</MessageCategoryId>
   <MessageCategoryName>Promotions</MessageCategoryName>
   <PreferenceStatus>OptedOut</PreferenceStatus>
   <LastModifiedDate>2026-08-04T20:15:00</LastModifiedDate>
  </UpdateContactMessageCategoryPreference>
 </Responses>
</ActionResponse>

Notes

• PreferenceStatus is OptedOut.
• Optional ID (with source) may be returned when a remote key is present.
• If already opted out, no additional opt-out is created; LastModifiedDate remains the existing modification time.

Opt In

Opts a contact back into a Message Category by deactivating the category-level opt-out (does not create a separate opt-in record). Idempotent if already available.

Request

<ActionRequest xmlns="http://partner.informz.net/aapi/2009/08/">
 <Brand id="2001">Example Brand</Brand>
 <User>apiuser</User>
 <Password>password</Password>
 <Actions>
  <UpdateContactMessageCategoryPreference>
   <Contact>
    <ContactId>10001</ContactId>
   </Contact>
   <MessageCategoryId>11</MessageCategoryId>
   <PreferenceAction>OptIn</PreferenceAction>
  </UpdateContactMessageCategoryPreference>
 </Actions>
</ActionRequest>

Response

<ActionResponse xmlns="http://partner.informz.net/aapi/2009/08/">
 <Brand id="2001">Example Brand</Brand>
 <User>apiuser</User>
 <Responses>
  <UpdateContactMessageCategoryPreference>
   <ActionStatus>
    <Status>success</Status>
   </ActionStatus>
   <ContactId>10001</ContactId>
   <Email>user@example.com</Email>
   <MessageCategoryId>11</MessageCategoryId>
   <MessageCategoryName>Promotions</MessageCategoryName>
   <PreferenceStatus>Available</PreferenceStatus>
   <LastModifiedDate>2026-08-05T14:30:00</LastModifiedDate>
  </UpdateContactMessageCategoryPreference>
 </Responses>
</ActionResponse>

Notes

• PreferenceStatus is Available.
• If an inactive opt-out row already exists, LastModifiedDate is that row's existing modified_date.
• If no opt-out row exists, LastModifiedDate is the current server time for the successful no-op.

Errors