…
Do you have Use default gw on the pptp-client? If so, check out your firewall and nat rules, that would explain both items.
…
Don’t know your specifics regarding ip addressing/routing tables/firewalls neither from your servers nor the device dialing the pptp-client; apparently your mikrotik firewall rules seem to be fine, so it’s definitely either a NAT, routing or servers firewall (if any) problem.
What addreses are those servers using?
What about their routing tables?
Do they use any sort of firewall?
A concise network diagram will make easier spotting the issue.
…
Other systems inside 192.168.0.0/24 can access the server with no issues, can access external with no issues.
Remote laptop can either access the internet (default gateway off) or can access the server by IP only (default gateway on). It can not access internal systems by name (NetBIOS or other).
You are facing several issues here:
Default Gateway for the pptp client: if you want to be able to browse the internet, and be able to communicate with the remote VPN network, you’ll had to disable “use default gateway”, and manually set routes to 192.168.0.0/24 through the PPTP connection after stablishing the VPN.
You say you can access it by IP, I understand you don’t mean just ping, but actually connecting to a samba share by using \192.168.0.118\share UNC notation.
If so, your problem lies on netbios name resolution; netbios by default uses Layer 2 for neighbour discovery, and you’re using a Layer 3 VPN, so you have to either:
Enable WINS on your samba server, so that netbios/CIFS uses layer 3 for name resolution.
Switch to a layer2 vpn protocol like L2TP.
Layer 3 will be definitely more efficient and prevents broadcasts to waste the vpn bandwidth, the choice is yours.
Is it generally a good practice to enable WINS and make all windows clients to use it to prevent broadcast on your network, it also makes network/share browsing snappier.
Check also the ppp profile used by the pptp client has proper DNS and WINS server filled in, and that the windows pptp connection is actually getting and using them.