E-mail

Once again I had problems with my e-mail account. It appeared that a lot of messages I have sent the last month(s) have not actually been sent! Or better: they never arrived. When sending they were accepted by the SMTP-server, but there they have been deleted.
The problem is that I am using some forwarded e-mail addresses like mail@jeroensangers.com and jeroen.sangers@fimcap.org. Mail send to these addresses are being forwarded to another mailbox, to which I connect with my mail program.
So far no problem, but I also want to send e-mail using the above adresses. Therefore I change the ‘from’ field in my mail application. But now, a lot of providers don’t allow this, to prevent spam. Usually, the SMTP server will reject your message, so your not able to send it. My latest provider however, accepted the messages, but didn’t sent it further (yes, to /dev/null!).
At the moment I am looking for a new provider. Until that, I will not be able to send my messages using jeroensangers.com or fimcap.org.
(Sorry for this quite tecnical message, but I know that at least half of my readers DOES understand it. If you don’t: just forget it…)