this is how it is done by Microsoft:
ExchangeService service = new ExchangeService(ExchangeVersion.Exchange2013_SP1)
{
Url = new Uri(value.outlookTokenInfo.ewsUrl),
Credentials = new OAuthCredentials(value.outlookTokenInfo.token)
};
and than:
Item item = Item.Bind(service, value.outlookTokenInfo.item);
as you can see to get an email item the authentication is done using a token and mail item id.
is there a similar way to do the same using mail.dll?