Third-party email providers often set limits on the number of emails you can send. I propose adding the ability to use multiple email addresses in a single session to increase these limits and prevent account suspensions.
Expected behavior
Ability to use multiple email accounts with automatic switching
Yes. Following through, the client could switch to the next relay:
based on round-robbin after each message (to also increase the delay between contacting the same server)
stochastically with probability adjusted by preset weights derived from the rate limit of each provider (gets a bit complicated if the relationship between the per minute, hourly and daily quotas differ)
dynamically acting upon rate limiting error messages
fallback in case the given relay is temporarily offline
I think some of these are already planned to be supported in a future version.
Also, it would be nice to have the possibility to set a different proxy for each relay account. Some providers block sending mail from particular proxies.
The ability to choose/force a particular relay to be used only for receiving or only for sending would also provide great flexibility for different use cases. For example: receive though a classic account and send though chat mail server. In such a case there would be no deadline to download received messages to all your devices, while not bearing with sending limitations of classic accounts. Chat mail relay would be managing a bit less traffic also…