Does the intention of divorce take effect upon writing an allusive phrase of divorce after sending it but before it is read, given that the intention was withdrawn before it was read?

The more accurate view is that writing a divorce (talaq) is a metaphorical expression (kinayah) that depends on the husband's intention. So, if the husband does not intend to effect a divorce when writing and sending it, then it does not occur. However, if he writes the divorce with the intention of it, his divorce takes effect, even if he does not send the message. The intention must be associated with the utterance when it is spoken.