Lobbying the EU seems inviting af first. Indeed all the MEP's have their contact-details posted on their website, and getting in touch with a policymaker seems like just an email away. So you start writing letters to MEP's and to your surprise they aren't getting back to you. After a while you are starte to wonder what you are doing wrong. Here is a small but not exhaustive list of why MEP's aren't responding to your letters/e-mails.
They simply haven't yet read your email.
MEP's sometimes receive hundreds of emails a day. These emails are filtered by their assistants, but even these busy bees can't handle the workload to cover everything. What you could do is call the assistents of the MEP and ask them if they have received the mail. This will make sure you at least know they have received it and bump it up in their unconscious list of letters to watch out for. If it something rather important (but I am mean really important, because in principle everything is important) what you could do is announce that you are going to write a letter. Call the assistant, ask them if they would rather receive the letter on their own email instead of the MEP's and explain in two sentences what the letter is about.
Wrong time, wrong place, wrong MEP: Your letter is irrelevant
Most of the letters and emails that MEP's receive are to inform them about a certain stake, project or region without asking them for direct and concrete action. All these letters end up in the trash bin. The same goes when you write them a letter asking them for their support but the MEP is not in the position (the right committee, or the right moment in the policy process) to help you. Don't expect an MEP to write you back if youre issue is already a lost battle. So ideally, you write to the MEP who is in the right committee to help you, at a moment when it actually matters.
Barking up the wrong tree: the MEP has opposing views of what you are asking from him
Are you sure the MEP is actually in favor of what you are asking from him? A little background check wouldnt hurt. An extreme example would be asking for support for nuclear power from a Green MEP. But every single case will have to be politically in line with the political values of the MEP, and to some extent of his political family. One way to check is by looking at votewatch,eu to see how the MEP or his political party voted on the issue in the past. Or simply do a background check by looking at his website or other resources.
You don't have the (political) clout
When a issue becomes "hot", the whole of Europe wil start contacting a handfull of MEP's. The MEP will then have to decide who to listen to to. He certainly won't be able to listen to each and every lobbyist or interest group calling him. What ussually hapens is that he makes a selection of "opinion leaders" on the issue. These opinion leaders range grom experts to political heavyweights. On the Common Agriculture Policy these could involve world class Universities like Wageningen but also interest groups like COPA-COGECA. All the small players will be disregarded (I am exagerating a bit). So if you want your voice to be heard in the midst of the battle, you should make sure you "bring a friend"which has the attention of the MEP. In case that you do not have the political weight to throw around, you should at least be an expert int he field.
There is nothing worst then having problems to acces a policymaker when you have a immediate and pressing issue. One thing you did wrong from the start is that the MEP apparently doesn't know you well enough to give you 5 minutes of his time. Therefore you should invest in buidling a relationship with an MEP (and just as important with his assistants) even before you have an issue. Seconly, pay great attention to detail. Is the letter you wrote personalized in order to make it relevant for the MEP you are adressing. You can forget about mass-mailings, they are only effective in hurting your reputation. Thirdly, make someone with political clout contacts the MEP. Lobbyists are the weakest pieces on the EU chessboard, its far more better when an CEO, a local politician or a ambssador contacts an MEP.