On Polaris platform, if you need to contact customers you have communicated with before, you can try the following methods:

1. directly search the contact information of the other company, and contact by phone or email.

2. If you know the user name of the other party, you can log on to Polaris platform and find the contact information of the other party through the pages of "Bidding and Purchasing" or "Online Trading".

3. If none of the above methods can get the contact information of the other party, you can try to enter the name or keywords of the other party's company on the "Find Information" or "Find Company" page of Polaris platform to further search for relevant information. Find the corresponding company page in the search results and check the contact information of the other party.

Please note that before contacting each other, it is best to understand each other's background and business needs in order to communicate better. At the same time, respect each other's wishes and privacy, and don't force sales or harass each other.