.net core version of System.Net.Mail is used when targeting .net461

Description

I want to add Suave.Experimental and target net461 but using .net sdk-based project.
When referencing System.Net.Mail.MailAddress class, a .net core package System.Net.Mail is added instead of using the standard System.dll 4.0

Repro steps

https://github.com/theimowski/repro-paket-system.net.mail

1. dotnet restore

2. dotnet build

3. dotnet run

Expected behavior

want to print:

System.Net.Mail.MailAddress, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089

Actual behavior

prints:

System.Net.Mail.MailAddress, System.Net.Mail, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null

Known workarounds

¯\(ツ)/¯

TBH I'm not even sure if this is Paket-related, or rather F#-specific.
Same happens if I don't use Paket on F# project: https://github.com/theimowski/repro-paket-system.net.mail/tree/fsharp_nopaket
However if I use C# without Paket https://github.com/theimowski/repro-paket-system.net.mail/tree/csharp , I get an error build upon dotnet build:

Program.cs(9,54): error CS0433: The type 'MailAddress' exists in both 'System.Net.Mail, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' and 'System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' 

Any guidance would be helpful here

Start with the linked repro-paket-system.net.mail repository and run dotnet restore, dotnet build, and dotnet run for the net461 F# project. Compare its F# and C# variants, including the C# build error, and verify that the final resolution uses System.dll without the duplicate System.Net.Mail assembly.