Ok, I'll try this.stanbusk said:Yes but intervals and groups are actually available to make it work on servers with strong security settings. I don't say it is the problem here but many web hosting companies are implementing very tight security mesures. In some servers uploading is not even possible until you ask them to allow it, this situation is rare but it can happen. What MaxBulk Mailer uses is a HTTP POST. Also note that your server may give you details on why an error is returned, that can be useful information in order to make it work.