I am wandering if the contacts added via an API can get a welcome email immediately or if they have to wait 12-24 hours for the autoresponder email.
When a contact is added to any account or updated from the Constant Contact API, we provide the option to specify if this is an action by the visitor(contact), or an action by the account owner. In the case of welcome emails, they are only sent when the API request to add a contact is specifically an action by the visitor rather than by the owner.
In order to specify this, you must add the action_by query parameter with the value ACTION_BY_VISITOR to your POST request to create the contact. You can find the details on this parameter as well as additional information about creating a contact here: http://developer.constantcontact.com/docs/contacts-api/contacts-collection.html?method=POST
Additionally, if you are using a specific code wrapper for our API, I am able provide direction on how to make this distinction within that wrapper. For this I would simply need to know what wrapper you are using and it would be helpful to have a short code snippet showing how you are creating the contact.
Lastly, if you do have any more questions or would like any additional information, please feel free to reply to this post and we will be happy to help!
Can the ACTION_BY_VISITOR parameter be specified for bulk add methods? Either through the API wrappers (the Java AddContactsRequest, for example) or manually?
Unfortunately, the ACTION_BY_VISITOR tag is specifically restricted to adding individual contacts. The reason behind this is that a welcome email is meant to be triggered as a reaction to a individual user action. A second reason for this behavior is that users who are unsubscribed from your account can only be added back through ACTION_BY_VISITOR, and we need a user's opt-in to be specifically tied to an individual action, rather than being part of a bulk action.
If you do have any other questions about this or if I can provide any additional info, please let me know!