Just to add that I also have a rule as above but for Postal service name equals UK_RoyalMail24
Thank you for raising this with us.
If you wish the system to correctly assign shipping services to your orders, then the best option would to use Channel Shipping Mapping in conjunction with Rules Engine. The problem with the way you are using Rules Engine at the moment is that you use a condition for Postal Service Name and specify an order Channel Shipping Tag as a value which cannot be used in Rules Engine (because essentially it is not a Postal Service Method). Instead, you need to use the actual Postal Service method names that you can find in Shipping -> postal Services.
To start with, you can perform channel Shipping Mapping. By doing this you will be able to assign Linnworks Postal Service methods to your eBay orders based on the Channel Shipping tags (like UK_RoyalMail24). Of course, as you said, the problem will remain with the mail sizes (LL, parcel, etc.). This is where Rules Engine will help.
As you have already said, you currently have some rules where the system should check for the Postal Service Methods - that is where you will need to apply some changes. You will need to amend the values from the Channel Shipping Tags to actual Linnworks Postal Services which you used in Channel Shipping Mapping. For example, change UK_RoyalMail24 to the actual Postal Service Method which was used in Channel Shipping Mapping (e.g. CRL: Royal Mail 24 Parcel). This will fix the issue with the system being unable to identify the correct orders - the system will be able to understand what orders it needs to look for when doing evaluation. Then, you will need to decide based on what conditions you want the system to assign the correct mail sizes (LL, parcel, etc.). As you said, you could use dimensions and weight.
Therefore, the system will first assign the Postal Services to your orders and then, based on further conditions (Dimensions, etc.) will be able identify using what service each and every order should go with (LL, Parcel, etc)
I can also see that my colleague has just replied to your ticket 1177311 where you discuss the issue.
Hope this helps.
I'm having no end of issues trying to get up and running with postage.
On eBay I offer customers a free option of Royal Mail 48 or an option to pay for Royal Mail 24.
Having checked the Order XML of some orders in "Ready to Process" I can confirm the ShippingService is is UK_RoyalMail24 and UK_RoyalMail48 respectively.
In my Rules engine I have created a rule the checks if Postal service name equals UK_RoyalMail48 it then moves on the check if the order meets the dimension and weights for Letter, Large Letter of Parcel and assigns the respective CRL Royal Mail 48 service.
All my orders show Carrier: NONE (Default) for shipping information and are not affected by the rules.
I have opened a couple of tickets and so far I have been told I need to assign a default postal service to each item in the inventory but if i set this to CRL : Royal Mail 48 Large Letter and an eBay order comes through where a customer as selected RM24 the order still shows as being RM48.
The second solution was use the Channel Shipping mapping and assign a Linnworks Postal Service to the Channel service. Again the issue with this is that I have to assign one mail size to any order coming from eBay with Royal Mail 48. If i followed this advice and mapped eBay's Royal Mail 48 to Linnworks CRL : Royal Mail 48 Large Letter then when an order that is a parcel comes in, this is still assigned as a Large Letter.
Can anyone tell me what I need to do as Linnworks staff are just pushing me towards handing a grand over to ebusinessguru to set it up instead of helping.