Sending an email by collection variable

Hi,

I am sending an email by collection variable and it is working fine.
My Collection variable contains the information like,
- colUserData[0] = 'abc@test.com;pqr@test.com;mno@test.com'
- colUserData[1] = 'jkl@test.com'
- colUserData[3] = 'pqr@test.com;jkl@test.com;'
- colUserData[4] = 'abc@test.com'

- colUserData[...] = 'xyz@test.com'

- colUserData[5000] = 'abc@test.com'

I just wanted to know,
Is there any limit to send email to users via collection variable?
How many recipients are allowed for sending an email nintex workflow?

Thanks,

Kalpesh