Company logo not showing in emails

I have set up an invoice, which prints out perfectly, showing company logo.  However when i choose email instead of print, the logo and footer is omitted.  Settings/invoice-default/email is set to my invoice. This has only recently gone wrong.  It was working previously.  Also previously each company's invoices were emailed as a company to the draft email folder, but now all the invoices are appearing on one long email to just one of the selected companies.  Also SAGE is defaulting to email address1 rather than the preferred email set up in address/contact preferences.