Hello, I have several email addresses which I use with different clients. I have my 1) personal gmail 2) main professional address which is my own ovh sever and a3) client email adress which is an external outlook address set up by my client. I use Tbird to manage all my email addresses in one spot. I have noticed a couple of times that I will receive replies on my gmail (address 1) even thought the email was sent from my other account. Not a very big deal, I thought I had made a mistake. However something bad happenned because an email I sent from my ovh email (address 2) arrived at one of my client as if coming from my address 3 (the one set up by my other client). It is a big problem for me professionally. I did not see the error but it was reported to me by the client who received the email from the wrong address and was very confused. I have been using both addresses extensively in the last few days and it has only seem to happen for that message. I did not hear about any similar pb with any other email I have sent. I have checked the following - I have checked the sent folder and the email I sent is only in the sent folder of address 2 - the correct one. - SMTP outgoing servers. They are all configured with the correct email address. The gmail smtp was set as default which may explain why some emails appear have been sent from gmail. I have now set it to address 2 which is my main address. - Outgoing server specified for each email address is the correct one I am now in a situation where my client is worried about confidentiality which is very problematic for me. How can I convinve myself and my client that this glitch will not occur again. Thanks