Q: Is it too early to contact the journal?
I have submitted a paper at AFRIKA Mathematika on 07 March, 2016, but until now the status of the paper is "with editor." So I have a question: Can I send an email to the journal or it is too early to contact them?
Your question is not very clear. Do you have a general question about your submission that you want to ask the editor? Or do you want to inquire about the progress of your paper and when it will be sent for peer review? In case you have a doubt or a question regarding any aspect of your submission, you can write to the journal at any point of time. However, if you want to know about the progress of your paper, it might be too soon to ask them. You should wait for at least another month, and if the status still remains the same, you can send an inquiry to the journal editor.