102: Invalid ClientId

[samritchie]

On a non-Agency account, attempting to send transactional email using a client constructed with Transactional.Authenticate.ByClientApiKey() fails with 102: Invalid ClientID. I was able to workaround using ByAccountApiKey() and supplying the account ClientID.

I’m unsure if this is the intended behaviour as there’s no documentation and no sample code, but it seems unlikely you would need an IAgencyTransactional client on a non-Agency account.