Hi Björn,
did you read the ROE located here.
Point 6!
Avoid solicitations. Avoid marketing your company’s products and services. If you want people to know your affiliation with your company, put those details in your profile to make the information available to the community. Do not embed links to ads in your posts. The same applies to email solicitations and advertising. If you want someone to trust you enough to buy what you offer, share your expertise and they will seek you out. If you want people to contact you, you can choose to make your email visible in your profile, but we ask you not to post it elsewhere on the site.
~Florian