I was facing an issue that no mails were arrived while sending invoices in PDF from a batch. Sending e-mails from a client worked fine. The reason is in enabled SMTP relaying on customer's mail server and in \Classes\RunbaseReportStd\serverSendMail method. This method calls quickSend() method from SysMailer class. The first parameter of this method is fromAddress. In this method this parameter is filled with same value as toAddress. This may cause that no mail will be delivered when SMTP server is configured to drop relayed mails.