Should we learn Tajweed or Qur'an from an imaam or teacher if he/she does not have an ijaazah?


Should we learn Tajweed or Qur'an from an imaam or teacher if he/she does not have an ijaazah?

I am asking this question as I believe there are many imams who teach Qur'an recitation or Tajweed, but do not themselves have an ijaazah, and could be teaching incorrect recitation.

Should we learn Qur'an recitation or Tajweed from them if they do not possess an ijaazah?

How do we know if someone has an ijaazah, what evidence do they show to the student?

Should we travel overseas to learn and obtain an ijaazah in tajweed?

I hope you can answer my questions.

Jazakallu Khair.

Wa alaikum assalaam wa rahmatullahi wa barakaatuh
There are many qualified teachers of the Qur'an who do not have an ijaazah, but read and teach well.  Having an ijaazah requires memorization of the whole Qur'an and not all Muslims are able to, or have not reached that goal yet, but can read the Qur'an properly and teach it well.
That being said, if someone has an ijaazah from a strong sanad, it is better to go to them, if possible.  It is not always possible to find a teacher with an ijaazah who is free to teach multiple students or individual students.  They may have many students and not be able to take on more.
When you obtain an ijaazah, you are almost always presented with a certification of the ijaazah which contains the sanad -meaning authentic chain of transmission from the one giving the ijaazah back through the chain one by one, naming each individual in the chain until it reached the Messenger of Allah, peace and blessings of Allah upon him. 

Whether you need to travel or not to seek obtaining an ijaazah depends on what is available in your area as far as qualified teachers with ijaazah.  If you have good teachers with ijaazah, it is not necessary to travel.  If however, you find there is a teacher with a stronger sanad and better at teaching and correcting in another country, then it is good to travel and get the ijaazah from them, if possible. 
May Allah grant you and all on the road to obtaining an ijaazah all khair and tawfeeq of Allah.
Wa iyyaakum.